JPH1021319A - Information reproducing device and reading optical system used by the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device which can be used in common for the information mediums of different recording density by moving an image pickup element on an optical axis to make a distance between the image pickup element and an optical system large (small) at the time of reading the information recording medium of high (low) recording density by a moving mechanism. SOLUTION: At the time of reading the information recording medium of high recording density, the image pickup element 14 is read by the moving mechanism 20 to increase the distance from the optical system 15 on the optical axis. On the other hand, at the time of reading the information recording medium of low recording density, the image pickup element 14 is read by the moving mechanism 20 to reduce the distance from the optical system 15 on the optical axis. Thereby, the information recording mediums of different recording density are image-formed and read on the element 14 always in a fixed and prescribed size. In this case, an object distance also changes but by adjusting the moving mechanism of a connection part 19, the distance from the time of the information reproducing device to the recording medium can be kept constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading optical system for imaging an information recording medium, which encodes multimedia information optically readable on paper, a resin film, a metal sheet or the like, into an image pickup apparatus. System, information reproducing device,
More particularly, the present invention relates to a reading optical system and an information reproducing apparatus capable of reading at different magnifications even when encoded information recording media are recorded at various densities.

[0002]

2. Description of the Related Art Various media other than magnetic tapes and optical disks are known as media for recording audio information such as voice and music. However, each of these media is somewhat expensive, even in large copies.
It requires some space for its storage. In the case where the medium on which the voice is recorded is delivered to another person at a remote place, someone takes it directly or mails it, and it takes time until the medium is delivered to the remote person. The same applies to audio information such as video information obtained from a camera or a video device or digital code data obtained from a personal computer or a word processor.

In view of such circumstances, Japanese Patent Application Laid-Open No. Hei 6-231466 filed by the present applicant has disclosed in Japanese Patent Application Laid-open No. An optically readable code (image), such as an encoded dot pattern, is recorded on so-called multi-media information such as digital code data obtained on paper, a resin film, a metal sheet, or the like. We have proposed an information processing system that irradiates this dot pattern with illumination light and reads the reflected light using optical means to reproduce the recorded multimedia information.

[0004] In this information processing system, multimedia information is recorded on paper or a sheet-like material equivalent thereto, which is considered to be the most economical medium. This is very useful for reducing the cost and space of the medium. Further, information recorded as a dot pattern can be easily transmitted by fax, and information can be easily transmitted to a remote person. This is very significant, especially for audio information, and the exchange of audio information, which was previously performed by passing the medium itself, can be instantly and easily performed with a remote person by this information system.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a reading optical system, an information reproducing apparatus, and an information recording medium of this information system. When recording on a medium such as paper, for example, when transmitting by fax or when encoding the voice with a personal computer, the recording device is a printer, and a recording device when placing an information recording medium on a book or magazine etc. Becomes a printing press. In particular, a printing machine or the like has a higher resolution than a printer or the like, and can print information at a higher density, so that the information recording density is made finer than an information recording medium printed by the printer. For this purpose, there are various specifications for the recording density of the information to be recorded in printing machines and simple printers, and the conventional reading optical system and information reproducing device use the one that reads the information recording medium at an appropriate imaging magnification. Was.

FIG. 24 shows the relationship between images on the image pickup device surface when a certain kind of reading optical system or an information reproducing apparatus having the same is used for information recording media having different recording densities. . In this figure, 1 is one pixel of the image sensor, and 1A is an image of one dot code.
The size of the image on the information recording medium is determined by the imaging magnification of the reading optical system. Therefore, the size of the image of one dot code on the information recording medium is different in size according to the recording density of the information recording medium.

When reading an information recording medium having a low recording density, as shown in FIG. 24A, when reading an information amount equivalent to that of an information recording medium having a large dot image size and a high recording density, In addition, the size of the image sensor placed on the image plane must be increased, which causes an increase in the size and cost of the apparatus. Further, when reading an information recording medium having a high recording density, as shown in FIG. 24B, the size of the image of one dot code is small, and the dot pitch is more than a certain degree with respect to the pixel pitch of the image sensor. When a small image is formed, the number of pixels assigned to the image sensor decreases, and a reading error occurs.

FIG. 2 shows a mechanism of a conventional information reproducing apparatus.
5 (A) and FIG. 25 (B), the information recording media 1 and 2 are printed with the encoded dot codes 1A and 2A. Here, it is assumed that the dot code 1A has a lower recording density than the dot code 2A. In the figure, the dot code 1A and the dot code 2A are drawn below the information recording media 1 and 2 for explanation, but are actually drawn on the information recording medium. Similarly, the dot code images 1B and 2B formed on the image sensor 4 are also drawn upward, but are actually formed on the image sensor surface.

In FIG. 25, when an encoded dot code of a predetermined recording medium is formed as an image of a predetermined size, that is, when the information recording medium can be read at an appropriate imaging magnification, for example, As shown in FIG. 25A, the image of the information recording medium code is larger than the image of the readable predetermined code, the pixel allocation of the image sensor to the code image is larger, and the same amount of information is read. For this purpose, the size of the image sensor increases.

Similarly, when an information recording medium having a higher density than a predetermined recording density, such as an encoded dot code 2A, is read from the information recording medium 2 having a high recording density in FIG. As described above, the image of the code on the information recording medium is smaller than a predetermined readable code, and the pixel assignment of the image sensor to the image of the code is reduced, thereby causing a reading error.

Further, when information recording media having different recording densities are read by one type of information reproducing apparatus as described above, the pixel assignment of the image pickup device to one dot error differs even in a range where no reading error occurs. Therefore, it is necessary to add a new circuit for processing this in an electric system, which increases the size of the information reproducing apparatus and increases the cost.

An object of the present invention is to provide a reading optical system and an information reproducing system capable of reading and reproducing information recording media of different sizes, that is, information recording media of different recording densities, using the same recording and reproducing device. An object of the present invention is to provide an apparatus and an information recording medium thereof.

[0013]

A first structure of an information reproducing apparatus according to the present invention is a device for reading an information recording medium on which predetermined information is recorded, and a photographing section for holding an image sensor at a predetermined position in a predetermined direction. A lens holding member for holding a holding member and a reading optical system, and a tip member arranged to keep a constant distance between the information recording medium and the tip of the information reproducing apparatus; The connecting part of the lens holding member, the connecting part of the lens holding part and the connecting part of the photographing part holding material have a moving function for moving the tip part and the lens holding member at predetermined positions along the optical axis. It is characterized by having.

According to the information reproducing apparatus of the first configuration of the present invention, when reading an information recording medium having a high recording density by the moving mechanism, the optical axis of the image pickup element is set so that the distance between the image pickup element and the optical system becomes large. When reading the information recording medium having a low recording density, the information recording medium having a different recording density is always moved to a predetermined size by moving the imaging element and the optical system so that the distance between the imaging element and the optical system becomes small. And can be read. In this case, the distance between the optical system and the information recording medium changes due to the change in the object distance, but the distance from the tip of the information reproducing apparatus to the information recording medium can be kept constant by moving the tip member by the moving mechanism.

According to another second aspect of the information reproducing apparatus of the present invention, an information recording medium on which predetermined information is recorded is read, and a reading optical system mounted on the information reproducing apparatus includes the information recording medium. A first lens holding member for holding the front group, a second lens holding member for holding the rear group, and an image pickup device at a predetermined position. And a moving mechanism configured to move the first lens holding member and the second lens holding member at predetermined positions along the optical axis. .

According to the second configuration, the first lens holding member and the second lens holding member can be moved by the moving mechanism to change the distance between the front group and the rear group of the optical system. Thereby, the imaging magnification can be changed without deteriorating the imaging performance of the reading optical system. The change in the position of the image plane due to the change in the imaging magnification of the entire reading optical system is as follows.
The image pickup device can be made to coincide with the position of the image plane of the reading optical system by the moving mechanism at the connection between the second lens holding member and the photographing holding member. When reading an information recording medium with a high recording density by this, by narrowing the interval between the front group and the rear group or when reading an information recording medium with a low recording density, by increasing the interval between the front group and the rear group, It is possible to always form an image on an information recording medium having a different recording density at a predetermined size and read the image.

A third configuration of the information reproducing apparatus of the present invention is an apparatus for reading an information recording medium on which predetermined information is recorded,
The reading optical system mounted on the information reproducing apparatus includes a front group and a rear group in order from the information recording medium side, and an optical unit for integrally fixing the front group and the image pickup device at a predetermined position and a predetermined direction; and And a lens holding member that holds
A connection mechanism between the lens holding member and the optical unit includes a moving mechanism movable at a predetermined position along an optical axis.

According to the third configuration, when reading an information recording medium having a high recording density, the distance between the front group and the rear group of the reading optical system is reduced, and when reading an information recording medium having a low recording density. By increasing the distance between the front group and the rear group of the reading optical system, information recording media having different recording densities can always be imaged and read at a fixed predetermined size.

Further, by changing the distance between the front group and the rear group,
Although the object distance changes and the distance from the reading optical system to the information recording medium changes, the distance from the information reproducing device to the information recording medium can be kept constant by the tip member provided with the moving mechanism. As described above, any information recording medium can be read by the same operation.

A fourth configuration of the information reproducing apparatus according to the present invention is for reading an information recording medium on which predetermined information is recorded, and the reading optical system mounted on the information reproducing apparatus includes the information recording medium. An optical unit comprising a front group and a rear group in order from the side, wherein one of the front group and the rear group and the image sensor are integrally fixed at a predetermined position in a predetermined direction, and a lens holding for holding the other group A lens group held by the lens holding member is formed of a transparent elastic body, and the lens holding member includes a mechanism for pressing a lens made of the transparent elastic body from a side surface. .

In the fourth configuration of the present invention, the image forming magnification of the reading optical system can be changed by changing the shape of the transparent elastic body by the pressing mechanism and changing the refractive power thereof. Therefore, when reading an information recording medium having a low recording density, the absolute value of the imaging magnification is reduced by increasing the inner diameter of the holding member, and when reading an information recording medium having a high recording density,
By reducing the inner diameter of the holding member and increasing the absolute value of the imaging magnification, information recording media having different recording densities can always be formed into an image of a predetermined size.

The present invention is characterized by an information recording medium which is read by using the information reproducing apparatus as described above. That is, the information recording medium of the present invention is characterized in that an index for determining the type of information recording density is provided on or near the recording medium.

Further, the present invention is characterized by the configuration of the reading optical system used in the information reproducing apparatus.

A first configuration of the reading optical system according to the present invention is as follows.
In order from the object side, the optical system has at least one aspherical surface in a two-group configuration including a front group of a lens having a convex surface facing the object side, a rear group of a positive lens having a convex surface facing the object side, and a stop. When reading information recording media having different recording densities, in order to change from a reading optical system having a small absolute value of the imaging magnification to a reading optical system having a large absolute value of the imaging magnification, Is increased to increase the distance between the information recording medium and the rear group, and satisfies the following conditions (1) to (4).

(1) −0.8 <β ₁ <−0.1 (2) −0.6 <Δds / f <1.5 (3) 0.05 <OH / d ₀ <1.60 (4) 0.005 <NA <0.08, where β ₁ is the imaging magnification in the first state, f is the focal length of the entire reading optical system, Δds is the distance from the principal point position of the entire reading optical system to the stop, OH is the height of the object, d ₀ is the distance from the information recording medium to the object-side surface of the first lens,
NA is the numerical aperture.

The condition (1) is a condition for downsizing the information reproducing apparatus. If the upper limit of -0.1 of the condition (1) is exceeded, the distance from the information recording medium to the image sensor becomes large, and the device becomes longer. On the other hand, when the value exceeds the lower limit of -0.8, the size of the image on the information recording medium becomes large, and accordingly, the size of the image sensor must be increased, which is not preferable.

The condition (2) defines the position of the stop of the optical system, and determines the angle between the off-axis ray and the optical axis. That is, when the information reproducing apparatus reads the recording medium, the apparatus is shaken in the optical axis direction, and the change in the imaging magnification that occurs at that time is reduced to prevent a reading error. When the value exceeds the upper limit of 1.5 of the condition (2), the angle between the off-axis ray entering from the information recording medium to the first surface of the lens of the reading optical system and the optical axis becomes large, and the imaging magnification changes. And reading errors tend to occur. When the lower limit of -0.6 is exceeded, the change in the imaging magnification is small, but the height of off-axis light rays incident on the first surface of the lens of the reading optical system from the information recording medium increases, and the size of the optical element increases. Absent.

The condition (3) is a condition necessary for arranging the illumination for reading the information recording medium at an appropriate position. If the upper limit of 1.60 of the condition (3) is exceeded, the position of the tip of the information reproducing apparatus that scans the information recording medium becomes too close to make it difficult to uniformly illuminate the information recording medium, resulting in uneven illumination. Is not preferred. In addition, in order to illuminate the entire recording medium, a new illumination optical system needs to be installed or a device having the same size as the information recording medium is required. If the lower limit of 0.05 of the condition (3) is exceeded, the distance between the information reproducing apparatus and the information recording medium becomes long, and strong illumination light is required, which is not preferable. Further, it is difficult to perform scanning while keeping the distance from the information recording medium to the leading end of the apparatus constant, and the operability of the apparatus deteriorates.

The condition (4) is a condition for using the information recording medium in an optimum state, that is, a condition for preventing a reading error. If the value exceeds the upper limit of 0.08 of the condition (4), the image of the information recording medium becomes bright, but the depth of field becomes shallow and a reading error is likely to occur, which is not preferable.
If the lower limit of 0.005 is exceeded, the brightness of the image on the information recording medium becomes dark, the ratio of noise to the read signal of the image formed on the image sensor increases, and the S / N ratio deteriorates. Read errors are more likely to occur.

As described above, an information recording apparatus that satisfies the above conditions (1) to (4) is desirable for achieving the object of the present invention.

Further, in the information recording apparatus of the present invention, it is desirable that the following conditions (5) to (8) are satisfied.

(5) 0.5 <| S ₁ | <12 (6) −0.5 <S ₂ <2.0 (7) 0.3 <d ₁ / f ₂ <3.0 (8) 0 .3 <d ₃ / f ₂ <2.5 where S ₁ and S ₂ are shaving factors S of the first lens and the second lens, respectively, and are given by the following equations, and d ₁ and d ₃ are The thicknesses f ₁ and f ₂ of the first lens and the second lens are the focal lengths of the first lens and the second lens, respectively.

[0033] _{S = (r a + r b} ) / (r a -r b) However r _a is the radius of curvature of the object side surface of the lens, is r _b is the radius of curvature of the image side surface of the lens.

The reading optical system mounted on the information reproducing apparatus of the present invention detects the presence or absence and the position of the two-dimensional dot code recorded on the information recording medium. Optics are preferred.

The condition (5) is for correcting distortion, in particular, and defines the shape of the first lens. When the value exceeds the upper limit of 12 of the condition (5), the off-axis principal ray is strongly bent to the optical axis side, and positive distortion is undesirably increased. On the other hand, if the lower limit of 0.5 is exceeded, the off-axis chief ray is bent in a direction away from the optical axis, and negative distortion increases, which is not preferable. In addition, when the position of the entrance pupil is shallow, the change in the imaging magnification when reading is undesirably large. Therefore, if the value is kept within the range of the condition (5), the distortion can be corrected with good balance.

Further, since the second lens of the reading optical system of the present invention is disposed immediately before the stop, it is possible to correct spherical aberration better than the shape of the second lens. The condition (6) is particularly for correcting spherical aberration, and is for defining the shape of the second lens. Exceeding the upper limit of 2.0 to condition (6) is not preferable because negative spherical aberration increases on the object-side surface of the second lens and negative spherical aberration generated by the second lens increases. In addition, the lower limit-
If it exceeds 0.5, negative spherical aberration generated on the image-side surface of the second lens becomes large, which is not preferable. As described above, the spherical aberration can be favorably corrected within the range of the condition (6).

The condition (7) is a condition necessary for downsizing and cost reduction of the information reproducing apparatus. The thickness of the first lens is determined by adjusting the thickness of the second lens having the main image forming action in the image forming optical system. This is standardized by the focal length. The condition (7) defines the thickness of the first lens. If the upper limit of the condition (7) exceeds 3.0, the thickness of the lens becomes large, the size of the apparatus increases, and the cost increases. . On the other hand, if the lower limit of 0.3 is exceeded, the thickness of the lens becomes too thin, making lens processing difficult, which is not preferable. Further, the height of the off-axis light rays emitted from the first lens cannot be suppressed low, and the distortion becomes worse. Therefore, the condition (7)
Within this range, the size and cost of the device can be reduced.

Condition (8) is also used to reduce the size or cost of the information reproducing apparatus, and specifies the thickness of the second lens. Exceeding the upper limit of 2.5 to condition (8) is undesirable because the thickness of the lens becomes large, the size of the apparatus increases, and the cost increases. Further, with respect to off-axis rays, particularly coma and astigmatism deteriorate, which is not preferable. On the other hand, if the lower limit of 0.3 is exceeded, the thickness of the lens becomes too thin, and production processing becomes difficult, which is not preferable. Further, if the power of the second lens becomes weak, the size of the apparatus becomes large, which is not preferable. As described above, within the range of the condition (8), the size and cost of the device can be reduced.

Another second configuration of the optical system used in the information reproducing apparatus of the present invention comprises a biconvex positive lens and an aperture in order from the object side, at least one surface of which is aspherical, and has a low recording density. When reading a different information recording medium, the reading optical system having a relatively small absolute value of the imaging magnification changes from a reading optical system having a relatively small absolute value of the imaging magnification to a reading optical system having a relatively large absolute value of the imaging magnification. An optical system that increases the distance between the lenses and reduces the distance between the lens second surface and the image sensor.
Condition (1) to condition (4) are satisfied.

The optical system of the second configuration also satisfies the conditions (1) to (4) and has the same meaning as that described in the optical system of the first configuration.

In the optical system having the second configuration, the following conditions (5-1) and (7-) are used instead of the conditions (5) and (7).
It is desirable to satisfy 1).

(5-1) -0.8 <S ₁ <0.4 (7-1) 0.2 <d ₁ /f<2.0 The condition (5-1) is particularly effective for distortion and astigmatism. It relates to correction of aberration, and defines the lens shape of the optical system. Conditions than the off-axis principal ray 0.4 upper limit is bent strongly toward the optical axis in the object side surface of the lens, when that is beta ₁ range therefore particularly imaging magnification is low (5-1) When the magnification is close to the upper limit, the distortion and the astigmatism are remarkably deteriorated, which is not preferable. If the lower limit of -0.8 is exceeded, the object-side surface of the lens does not have an image-forming effect, and it becomes impossible to correct astigmatism and distortion generated on the image-side surface. In particular, distortion caused by the positive power of the image-side surface increases, which is not preferable. That is, distortion and astigmatism can be corrected within the range of the condition (5-1).

The condition (7-1) is a condition for reducing the size or cost of the information reproducing apparatus, and defines the thickness of the lens of the optical system. When the value exceeds the upper limit of 2.0 to condition (7-1), the thickness of the lens becomes large, the device becomes large, and the cost increases. On the other hand, when the lower limit of 0.2 is exceeded, the thickness of the lens becomes small, and the production processing of the lens becomes difficult. As described above, if the value is within the range of the condition (7-1), the size and cost of the device can be reduced.

The third configuration of the optical system according to the present invention comprises, in order from the object side, a meniscus lens having a convex surface facing the object side, a positive lens having a convex surface facing the object side, and a stop.
A reading optical system having at least one aspherical surface and having a relatively small absolute value of the imaging magnification when reading information recording media having different recording densities; An optical system for reducing the distance between the two lenses of the reading optical system as the system becomes closer, and satisfies the conditions (1), (2), (3) and (4).

Also in the case of the optical system having the third configuration, it is desirable to satisfy the conditions (1) to (4) for the above-mentioned reason.

Also, when reading an information recording medium having a low recording density by using an optical system in which the distance between the front group and the rear group does not change in a normal reading optical system, the distance from the information recording medium is longer than the distance when reading the high density one. Unless the distance to the image sensor is increased, reading cannot be performed at an appropriate imaging magnification. However, since the group spacing of the reading optical system is variable, when reproducing information recording media of different densities, the distance from the information recording medium to the image pickup device does not need to be largely changed, so that an information recording medium having a low recording density can be used. Even when reading, the optical system can be made compact, which is advantageous for miniaturization of the information reproducing apparatus.

Furthermore, the reading optical system of the third configuration of the present invention is different from the condition (5) in the following conditions (5-2) and (6).
Satisfies the following condition (6-1), and the condition (7):
It is desirable to fully store (8).

(5-2) 1.2 <| S ₁ | <12 (6-1) -0.5 <S ₂ <4.0 The fourth optical system of the reading optical system according to the present invention is provided on the object side. In order, the imaging magnification when reading an information recording medium having at least one aspheric surface in a two-group configuration including a biconcave lens, a positive lens having a convex surface facing the object side, and an aperture, and having different recording densities. The distance between the two lenses constituting the optical system decreases as the reading optical system has a relatively small absolute value and the reading optical system has a large absolute value of the imaging magnification. 1), (3), (4) and the following condition (10) are satisfied.

(10) -10.6 <f ₁ / f ₂ <−0.5 This condition (10) is for shortening the distance from the information recording medium to the image pickup device, and the first condition of the reading optical system. This defines the distribution of the combined focal length of the lens (biconcave lens) and the second lens (positive lens with the convex surface facing the object side). If the upper limit of -0.5 of the condition (10) is exceeded, the distance from the information recording medium to the image sensor can be shortened, but the angle formed by the off-axis principal ray from the information recording medium with the optical axis becomes large. Therefore, when reading the information recording medium, if the apparatus is shaken in the optical axis direction, the change in the imaging magnification becomes large, and a reading error is likely to occur, which is not preferable. If the lower limit of -10.6 of the condition (10) is exceeded, the combined focal length of the entire reading optical system becomes undesirably long. In addition, the height of the off-axis principal ray cannot be suppressed low, and the size of the optical element constituting the reading optical system is undesirably increased.

It is preferable that the optical system of the fourth configuration also satisfies the conditions (1), (3) and (4) for the same reason as described above.

Since the distance between the two lenses is variable, when reproducing information recording media having different recording densities, the distance from the information recording medium to the image pickup device does not need to be largely changed. Therefore, even when reading an information recording medium having a low recording density, it is advantageous for miniaturizing an information reproducing apparatus capable of making the optical system compact.

Further, the reading optical system of the present invention can satisfy the following conditions (5-3), (6-1), (7-1) and (8)
It is desirable to satisfy

(5-3) -0.8 <S ₁ <0.6 (6-1) -0.5 <S ₂ <4.0 (7-1) 0.15 <d ₁ / f ₂ < 2.50 A fifth configuration of the reading optical system according to the present invention includes, in order from the object side, a meniscus lens having a convex surface facing the object side and a biconvex positive lens stop made of a rubber-like transparent elastic body. When reading information recording media with different recording densities in a
This is an optical system that changes the curvature of a biconvex lens made of an elastic body in the rear group to change the magnification of the optical system, and is an optical system that can be used in the fifth configuration of the information reproducing apparatus of the present invention described above. .

The optical system having the fifth configuration also has the above condition (1).
It is desirable to satisfy (4).

In the above-described optical system having the first configuration of the present invention, the following condition (1−1) is used instead of conditions (1) to (4).
If 1), (2-1), (3-1), and (4-1) are satisfied, it is possible to reduce the size of the information reproducing apparatus and prevent a reading error of the apparatus.

Instead of the conditions (5), (6), (7), and (8), the following conditions (5-4), (6-2), (7-2),
If (8-1) is satisfied, the spherical aberration of the optical system will be increased,
Astigmatism, distortion, and coma can be corrected in a well-balanced manner.

(5-4) 1.0 <| S ₁ | <8.0 (6-2) -0.2 <S ₂ <1.4 (7-2) 0.6 <d ₁ / f ₂ <2.2 (8-1) 0.4 <d ₃ / f ₂ <1.8 In the optical system having the second configuration of the present invention, the condition (1)
Conditions (1-1), (2) instead of (2), (3) and (4)
It is desirable to satisfy (-1), (3-1), and (4-2).

In the optical system having the second configuration, the condition (5-
Instead of (5) and (7-1), the following conditions (5-4) and (7-
It is desirable to satisfy 3).

(5-5) -0.6 <S ₁ <0.2 (7-3) 0.3 <d ₁ /f<1.5 In the optical system of the third configuration of the present invention, the condition (1),
Instead of (2), (3), and (4), conditions (1-1),
It is preferable to satisfy (2-2), (3-2), and (4-1).

In the optical system having the third configuration, the condition (5-
It is preferable to satisfy the following conditions (5-6), (6-3), (7-3), and (8-2) instead of (2), (6-1), (7), and (8). .

(5-6) 1.0 <| S ₁ | <8.0 (6-3) -0.2 <S ₂ <3.0 (7-3) 0.6 <d ₁ / f ₂ <2.5 (8-2) 0.45 <d ₃ / f ₂ <2.0 In the optical system of the fourth configuration, the conditions (1) and (1
0) Instead of (3) and (4), conditions (1-1) and (10-
It is desirable to satisfy 1), (3-3), and (4-2).

In the optical system having the fourth configuration, the condition (5)
Instead of (6), (7) and (8), the following conditions (5-7),
It is desirable to satisfy (6-5), (7-4), and (8-3).

(5-7) -0.7 <S ₁ <0.4 (6-5) -0.1 <S ₂ <2.2 (7-4) 0.25 <d ₁ / f ₂ < 1.50 (8-3) 0.4 <d ₃ / f ₂ <1.4 Further, in the optical system of the fifth configuration, the condition (1)
Conditions (1-1), (2) instead of (2), (3) and (4)
-2), (3-3) and (4-1) are preferably satisfied.

The aspherical surface used in the reading optical system of the present invention is such that the x-axis direction is x, the direction orthogonal to the optical axis is h, the on-axis curvature is C, and the aspherical surface coefficients are a ₄ and a _6. Is represented by the following equation.

By using an aspherical shape expressed up to the sixth order term as in the above equation, the shape becomes simple and processing is easy. If the aspherical surface shape is represented by an eighth-order term, the shape of the aspherical surface becomes complicated, processing becomes difficult, and the manufacturing cost increases.

The aspherical surface used in the reading optical system of the present invention may be used on any surface of the lens, but is preferably provided on the object side surface. In the reading optical system of the present invention, unlike the collimator lens described in JP-A-7-146438, since the height of an object having a relatively small NA is large, aberration correction of off-axis rays becomes important. .
Therefore, the use of an aspherical surface at a high position of off-axis rays, that is, the surface on the object side is advantageous for correction of off-axis aberrations. If both surfaces are aspherical, it is more advantageous for aberration correction.

It is desirable that the aspherical coefficients a ₄ and a ₆ satisfy the following conditions.

(11) 0.0001 <| a ₄ | <0.1 (12) 0.0001 <| a ₆ | <0.01 Conditions (11) and (12) are good for aberrations of off-axis rays. This defines the amount of deviation from the reference spherical surface.

If the lower limits of the conditions (11) and (12) are exceeded, the astigmatism will be insufficiently corrected, and the distortion will become a large positive value, which is not preferable. If the upper limits of the conditions (11) and (12) are exceeded, the astigmatism will be overcorrected, and the distortion will become a large negative value, which is not preferable. As described above, when a ₄ and a ₆ are within the range of these conditions, spherical aberration, astigmatism, and coma can be corrected with good balance.

[0070]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the information reproducing apparatus of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a first configuration of an information reproducing apparatus according to the present invention. FIGS. 1A and 1B show the configuration of an information reproducing apparatus when the recording densities of information recording media are different. It is. In the figure, reference numerals 11 and 12 denote information recording media, respectively.
A, information recording media of different recording densities such as 12A, 1
Reference numeral 3 denotes an image of the information recording medium, 14 denotes an image sensor, 15 denotes a reading optical system, 16 denotes a lens holding member that holds the optical system 15, 17 denotes a photographing unit holding member that holds the image sensor 14, 1
Reference numeral 8 denotes a tip member for keeping a constant distance between the information recording media 11 and 12 and the tip of the information recording apparatus. Reference numeral 19 denotes a moving mechanism provided at a connection portion between the distal end member 18 and the lens holding member 15, and 20 denotes a lens holding member 16
A moving mechanism 20 is provided at a connection between the optical recording medium 11 and the optical holding unit 15.
The connection part 20 is for adjusting the distance between the optical system 15 and the photographing unit (the image sensor 14).

That is, when reading an information recording medium having a high recording density, as shown in FIG.
When the distance on the optical axis from the reading optical system 15 is increased by the moving mechanism 20, and when an information recording medium having a low recording density is read, as shown in FIG.
The image pickup element 4 is moved by the moving mechanism 20 to the reading optical system 15.
The distance on the optical axis from the optical recording medium is made small, so that information recording media of different recording densities can always be imaged on the image sensor with a fixed predetermined size and can be read. In this case, the object distance also changes.
By adjusting the moving mechanism 9, the distance between the recording medium and the tip of the information reproducing apparatus can be kept constant. By these operations, any information recording medium can be read.

Next, an embodiment of the second configuration of the information reproducing apparatus of the present invention described above is shown in FIG. In the apparatus shown in this figure, when reading the information recording medium 11 on which the predetermined information shown in FIG. 2A is recorded and the information recording medium 12 having a recording density different from that shown in FIG. 1
An image pickup unit holding member 28 for holding the image sensor 14 for converting 3 into an electric signal at a predetermined position and in a predetermined direction, and a front group 23 and a rear group 24 constituting a reading optical system for forming an image on an information recording medium. The first lens group holding member 26 and the second holding member 27 are respectively provided. Then, a first moving mechanism 29 provided at a connection portion between the front group holding member 26 and the rear group holding member 27, the rear group holding member 27, and the photographing unit holding member 28
And a second moving mechanism 30 provided at a connection portion between the first moving mechanism and the second moving mechanism. Among these moving members 29, 30, the first moving mechanism 29 is for moving the front group 23 of the reading optical system in the optical axis direction, thereby changing the interval between the front group 23 and the rear group 24. The imaging magnification can be changed without deteriorating the imaging performance due to zooming. The second moving mechanism 30 can move the image sensor 14 in the optical axis direction, and when the imaging magnification of the entire reading optical system changes and the position of the image plane changes, the image plane of the reading optical system changes. The position of the image sensor can be matched.

As a result, when reading an information recording medium with a high recording density, as shown in FIG. When the distance between the group 23 and the rear group 24 is set to be small and an information recording medium having a low recording density is read,
By increasing the distance between the front group holding member and the rear group holding member, the distance between the front group 23 and the rear group 24 is increased, so that information recording media having different recording densities are always imaged at a predetermined size. Made and readable.

When reading an information recording medium having a low recording density by using an optical system in which the distance between the front group and the rear group of the optical system does not change, it is more difficult to read the information recording medium than to read the information recording medium having a high recording density. If the distance between the front group and the rear group is variable as in the second configuration, an information recording density of a different recording density is reproduced if the distance between the front group and the rear group is variable as in the second configuration. In this case, the distance from the information recording medium to the image sensor does not need to be largely changed, so that the optical system can be made compact even when reading an information recording medium having a low recording density, which is advantageous for miniaturization of the information reproducing apparatus.

The third configuration of the information reproducing apparatus according to the present invention is as shown in FIG. The information reproducing apparatus having the third configuration includes an optical unit 31 for integrally fixing the front group 23 of the reading optical system and the image pickup device 14 at a predetermined position and a predetermined direction.
And a lens holding member 32 that holds the rear group 24 of the optical system. Then, the rear group 24 is moved in the optical axis direction by a moving mechanism that moves the lens holding member 32. By moving the rear group 24, the group distance between the front group and the rear group of the optical system can be changed, thereby changing the imaging magnification while minimizing the deterioration of the imaging performance due to the change in the magnification of the entire optical system. Can be done. Therefore, when reading an information recording medium having a high recording density, as shown in FIG. 3B, when the distance between the front group 23 and the rear group 24 of the reading optical system is reduced, and when reading an information recording medium having a low recording density, By increasing the distance between the front group 23 and the rear group 24 as shown in FIG. 3A, it is possible to always form and read information recording media having different recording densities in a predetermined size. Become. That is, the same operation and effect as in the first configuration and the second configuration can be realized. Further, the front unit 23 of the optical system and the image pickup device 14 are fixedly arranged on the optical unit 31, so that the distance from the front unit 23 of the optical system to the image pickup device 14 is always constant, and the lens holding the rear unit 24 is provided. Since only the holding member 32 needs to be moved, manufacture and assembly of the product are extremely simple.

FIG. 4 shows a fourth configuration of the information reproducing apparatus of the present invention. In the figure, 35 is an optical unit,
36 is a lens holding member, and the optical unit 35 has a front group 3
3, a holding member 36 for holding the rear group 34, and the imaging device 1
4 is attached. The lens holding member 36 is held so as to be movable in a direction perpendicular to the optical axis with respect to the optical unit 35, and is pressed toward the axis (inward of the optical unit 35) by the pressing mechanism 37. The optical system includes a front group 33 and a rear group 34, of which the rear group 34 is formed of a transparent elastic lens.

In the fourth configuration, the pressing mechanism 37
As a result, the inner diameter of the lens holding member 36 can be expanded and contracted due to a shift in a direction (radial direction) perpendicular to the optical axis, thereby changing the shape of the transparent elastic lens (rear group).
This change in the shape changes the refractive power of the lens (rear group), thereby making it possible to change the imaging magnification of the reading optical system without deteriorating the performance. In other words, when reading an information recording medium having a low recording density, as shown in FIG. 4A, the inner diameter of the lens holding member 36 is increased to reduce the refractive power of the lens made of a transparent elastic body, thereby forming an image of the entire optical system. When reading the information recording medium having a high absolute value of the magnification and a high recording density, the inner diameter of the lens holding member 36 is reduced by the pressing mechanism 37 as shown in FIG. By increasing the refractive power of the optical system 34 to increase the absolute value of the imaging magnification of the entire optical system, it is possible to always form an image on an information recording medium having a different recording density with a fixed predetermined size and to read the information. .

As a mechanism for pressing the transparent elastic body 34 in the fourth configuration of the information reproducing apparatus of the present invention, the mechanism shown in FIG. 10 can be considered. As shown in this figure, the lens holding member 54 includes a pressing mechanism 52 for pressing the lens 34, and by moving the moving member 51, the lens holding member 54 is pressed from the lens holding member 54 in a direction perpendicular to the optical axis. The pressing mechanism 52 is operated so as to protrude.

When reading information recording media having different information recording densities, the information reproducing apparatus having the fourth configuration can easily read the lens 3 made of a transparent elastic body of the reading optical system by a simple operation.
The information recording medium can be read at a predetermined imaging magnification by changing the shape of No. 4.

FIG. 5 shows a fifth configuration of the information reproducing apparatus according to the present invention, in which 40 is a lens constituting a reading optical system, 41 is a lens holding member for holding the lens 40, 42
Denotes a photographing unit holding member, 43 denotes a tip member, and 44 denotes a moving member. A projection 41a is formed on the lens holding member 41, a cam groove 44a having a shape shown in FIG. 6 is formed on the moving member 44, and the projection 41a is inserted into the cam groove 44a. Therefore, by rotating the moving member 44 with respect to the photographing unit holding member 42 and the tip member 43, the lens holding member 41 and thus the lens 40 move along the optical axis as shown by the arrows in the figure. Thereby, the information recording medium having a high recording density shown in FIG. 5B can be changed from a state in which the absolute value of the imaging magnification of the optical system suitable for reading the information recording medium having a low recording density shown in FIG. In a state where the absolute value of the imaging magnification for reading is large, it is possible to read the image at a predetermined fixed size.

FIG. 7 shows another embodiment of the fifth configuration of the apparatus according to the present invention, in which the reading optical system includes a front group 23 and a rear group 2.
4, each of which is a first lens holding member 41 '.
And a second lens holding member 41 ″. Both the first and second lens holding members have a projection 41 ′.
a, 41''a. Two grooves 44a, 44b are formed in the moving member 44 as shown in FIG. 8, and a projection is inserted into each of the grooves 44a, 44b. ing.

In the apparatus shown in FIG. 7, the front group 23 and the rear group 24 move along the optical axis as shown by arrows by rotating the moving member 44 in the same manner as that shown in FIG. FIG. 7 (A) for reading an information recording medium having a low recording density.
The reading optical system changes from the state shown in FIG. 7 to the state shown in FIG. 7B for reading an information recording medium having a high recording density.
As a result, it becomes possible to read the information recording media having different recording densities at a constant desired size by changing the imaging magnification of the optical system.

FIG. 9 shows another example of the device having the fifth configuration.
Similarly, the reading optical system includes a front group 23 and a rear group 24. In the example of this figure, the front group 23 is
7 in that only the rear group 24 is moved in the optical axis direction by the rotation of the moving member 48.
Configuration is different.

Also in the apparatus shown in FIG. 9, the state shown in FIG. 9A for reading an information recording medium having a low recording density is changed to the state shown in FIG. 9B for reading an information recording medium having a high recording density. Thereby, by moving the rear group in the optical system, it is possible to read information recording media having different recording densities at a constant desired size.

FIG. 11 is a diagram showing an information recording medium of the present invention, wherein (A), (B) and (C) show different types (different recording densities) of information recording media. Each of these information recording media has an index 61.
1 is a code 62 encoding information recorded on the recording medium
The type or the recording density of the information recording medium can be visually determined by the index 61. The above code is recorded at such a high density that the type and the recording density cannot be visually discriminated, so that it becomes a material for judging the specification of the information reproducing apparatus when reproducing the information by this index, The information (recording) reproducing apparatus of the present invention can be used to read an appropriate fixed size.

FIG. 12 shows a recording / reproducing apparatus for reading an information recording medium having a predetermined recording density at a predetermined desired size, and a predetermined type of recording is performed by an index 65 provided on an exterior surface 63 of the recording / reproducing apparatus. It can be confirmed that the device has a high density. The display on the recording / reproducing apparatus and the display on the recording medium confirm that the recording medium has a predetermined density or type, so that the predetermined information recording medium can be easily read at an appropriate imaging magnification. Become like

FIG. 13 shows an information reproducing apparatus for reading an information recording medium, which can easily read information recording media having different information recording densities at an appropriate magnification. That is, the moving member can be rotated along the outer periphery of the information reproducing apparatus, so that the information reproducing apparatus can read at different magnifications. A mark 67 is formed on the provided or information reproducing device 68. With this index, it is possible to visually determine which type and density of the information recording medium can be read at an appropriate magnification.

In FIG. 13, the index is set to the moving member 6.
6 may be provided on the exterior 68 of the information reproducing apparatus. In that case, it is desirable that the mark 67 be described on the moving member 66.

The moving member does not rotate with respect to the optical axis along the outer periphery of the information reproducing apparatus, and may have an index as shown in FIG. Is possible.

When such an index is applied to the recording / reproducing apparatus shown in FIG. 1, the side surface of the lens holding member 16 between the lens holding member 16 and the moving mechanism 19, the lens holding member 16 and the photographing unit holding By providing the side of the photographing unit holding member between the members 17, it is possible to know in the information reproducing apparatus having the configuration shown in FIG. 1 that the apparatus can read an information recording medium of any specification. I can do it.

Similarly, in the case of the information reproducing apparatus shown in FIG.
By providing an index on the surface of the moving member 44 and aligning it with a mark as shown in FIG. 13, it is possible to know which information recording medium is suitable for reading. That is, when the index of the moving member 44 is rotated to match the mark, the location of the groove 44a or 44a, 44b formed on the back surface of the moving member as shown in FIGS. 6 and 8, for example, moves in the optical axis direction. The optical system moves so that the information recording medium indicated by the index can be read. As a result, a member of the information reproducing apparatus moves to a state where a person using the information reproducing apparatus can easily read a different information recording medium simply by setting the position of the index to the information recording medium to be read.

As described above with reference to the information reproducing apparatus of FIG. 1, for example, the instruction shown in FIG. By providing members, optical units, etc.,
The user can easily determine what kind of information recording medium the information reproducing apparatus is suitable for reading, that is, what the image forming magnification of the optical system is.

Next, an embodiment of the reading optical system of the present invention suitable for use in the information reproducing apparatus of the present invention will be described. Example _{1 f = 7.7149, f 1 =} -182.1572, f 2 = 6.6974 r 1 = 19.2478 ( _{aspherical) d 1 = 7.3836 n 1 =} 1.48978 ν 1 = 57.66 r 2 = 13.8355 d 2 = 5.3029 r 3 = 3.3759 ( _{aspherical) d 3 = 6.5446 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -42.0024 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 Aspheric coefficient (first surface) a ₄ = 3.5359 × 10 ⁻⁵ , a ₆ = −1.2543 × 10 ⁻⁶ (third surface) a ₄ = −1.7739 × 10 ⁻³ , a ₆ = −1.3532 × 10 ^{− 4} β _i -0.2700 -0.3600 -0.5401 d ₀ 24.2861 17.1431 10.0000 d ₅ 3.3946 4.0889 5.4778 Δds / f 0.6614 0.6614 0.6614 OH / d ₀ 0.3203 0.3392 0.3868 NA 0.01106 0.01286 0.01534 s ₁ = -6.1126, s ₂ = 0.8512, d ₁ / f ₂ = 1.1025, d ₃ / f ₂ = 0.9772

Example 2 f = 8.5435, f ₁ = -23.4741, f ₂ = 5.6728 r ₁ = 8.4353 (aspherical surface) d ₁ = 8.1044 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 3.3287 d ₂ = 4.4191 r ₃ = 2.9175 _{(aspherical) d 3 = 6.5073 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -15.5444 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν ₃ = 60.00 Aspheric coefficient (first surface) a ₄ = 1.1056 × 10 ⁻⁴ , a ₆ = −2.5490 × 10 ⁻⁶ (third surface) a ₄ = −2.3167 × 10 ⁻³ , a ₆ = −1.9350 × 10 ^-4 β _i -0.2764 -0.3667 -0.5447 d ₀ 24.0000 16.3888 8.7755 d ₅ 4.5379 5.3094 6.8299 Δds / f 0.5929 0.5929 0.5929 OH / d ₀ 0.3184 0.3498 0.4388 NA 0.01130 0.01309 0.01551 s ₁ = -2.33037, s ₂ = 0.6839, d ₁ / f ₂ = 1.5370, d ₃ / f ₂ = 1.1471

Example 3 f = 6.0522, f ₁ = -5.0062, f ₂ = 4.0755 r ₁ = 65.5704 (aspherical surface) d ₁ = 5.3633 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 2.3000 d ₂ = 1.4262 r ₃ = 2.1722 _{(aspherical) d 3 = 5.0320 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -5.8691 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν ₃ = 60.00 Aspherical surface coefficient (first surface) a ₄ = 8.6195 × 10 ⁻⁴ , a ₆ = −1.9662 × 10 ⁻⁵ (third surface) a ₄ = −6.5120 × 10 ⁻³ , a ₆ = −9.8050 × 10 ^-4 β _i -0.2700 -0.3600 -0.5400 d ₀ 21.0060 15.4021 9.7982 d ₅ 6.1317 6.6764 7.7658 Δds / f 0.0419 0.0419 0.0419 OH / d ₀ 0.3701 0.3789 0.3975 NA 0.01034 0.01285 0.01701 s ₁ = -1.0727, s ₂ = 0.4597, d ₁ / f ₂ = 1.3160, d ₃ / f ₂ = 1.2347

Example 4 f = 7.4074, f ₁ = -17.1622, f ₂ = 4.3489 r ₁ = 5.7586 (aspherical surface) d ₁ = 6.2341 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 2.2011 d ₂ = 1.1701 r ₃ = 2.4020 _{(aspherical) d 3 = 5.8341 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -3.7902 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν ₃ = 60.00 Aspherical surface coefficient (first surface) a ₄ = 2.1767 × 10 ⁻⁴ , a ₆ = −1.6191 × 10 ⁻⁶ (third surface) a ₄ = −4.5520 × 10 ⁻³ , a ₆ = −2.9283 × 10 ^-4 β _i -0.2703 -0.3604 -0.5404 d ₀ 23.4925 16.6445 9.7965 d ₅ 3.3546 4.0216 5.3552 Δds / f 0.6418 0.6418 0.6418 OH / d ₀ 0.3287 0.3480 0.3951 NA 0.01089 0.01287 0.01573 s ₁ = -2.2375, s ₂ = 0.2242, d ₁ / f ₂ = 1.4335, d ₃ / f ₂ = 1.3415

Example 5 f = 5.5911, f ₁ = −8.6229, f ₂ = 3.6041 r ₁ = 6.8710 (aspherical surface) d ₁ = 4.1475 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 2.0965 d ₂ = 0.4339 r ₃ = 2.7225 d ₃ = 4.7957 n ₂ = 1.59995 v ₂ = 60.70 r ₄ = -3.5672 d ₄ = 0.1000 r ₅ = ∞ (aperture) d ₅ = variable r ₆ = ∞ d ₆ = 2.0000 n ₃ = 1.53714 v ₃ = 60.00 Aspheric coefficient a ₄ = -3.5299 × 10 ^-4 , a ₆ = 1.9318 × 10 ^-5 β _i -0.2700 -0.3600 -0.5400 d ₀ 19.8540 14.6770 9.5000 d ₅ 3.6689 4.1721 5.1785 Δds / f 0.3811 0.3811 0.3811 OH / d ₀ 0.3934 0.3983 0.4092 NA 0.01061 0.01285 0.01629 s ₁ = −1.8782, s ₂ = 0.1343, d ₁ / f ₂ = 1.1508, d ₃ / f ₂ = 1.3306

Example 6 f = 5.7812, f ₁ = -12.3053, f ₂ = 3.4781 r ₁ = 3.9266 (aspheric surface) d ₁ = 3.4037 n ₁ = 1.48978 v ₁ = 57.66 r ₂ = 1.7000 d ₂ = 1.7648 r _{3 = 1.9185 d 3 = 2.4499 n 2} = 1.48978 ν 2 = 57.66 r 4 = -8.8181 d 4 = 0.0198 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 Aspheric coefficient a ₄ = -9.9199 × 10 ^-4 , a ₆ = 5.8429 × 10 ^-5 β _i -0.2700 -0.3600 -0.5400 d ₀ 21.4617 16.1086 10.7555 d ₅ 3.8919 4.4121 5.4528 Δds / f 0.3717 0.3717 0.3717 OH / d ₀ 0.3622 0.3623 0.3617 NA 0.01054 0.01285 0.01646 s ₁ = −2.5270, s ₂ = 0.6426, d ₁ / f ₂ = 0.9786, d ₃ / f ₂ = 0.7044

Example 7 f = 6.0127, f ₁ = -21.2671, f ₂ = 3.4650 r ₁ = 3.5796 (aspherical surface) d ₁ = 3.9797 n ₁ = 1.48978 v ₁ = 57.66 r ₂ = 1.6904 d ₂ = 2.1853 r _{3 = 1.7358 d 3 = 1.8099 n 2} = 1.48978 ν 2 = 57.66 r 4 = -50.0000 d 4 = 0.2697 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 aspherical coefficients ^{_{a 4 = -6.9005 × 10 -4,}} a 6 = -9.4808 × 10 -5 β i -0.2700 -0.3600 -0.5400 d 0 21.4458 15.8787 10.3115 d 5 3.3095 3.8506 4.9329 Δds / f 0.5032 0.5032 0.5032 OH / d 0 0.3620 0.3667 0.3748 NA 0.01077 0.01285 0.01594 s ₁ = −2.7895, s ₂ = 0.9329, d ₁ / f ₂ = 1.1486, d ₃ / f ₂ = 0.5224

Example 8 f = 7.5028, f ₁ = -145.2720, f ₂ = 6.0985 r ₁ = 13.5456 (aspherical surface) d ₁ = 7.6286 n ₁ = 1.48978 v ₁ = 57.66 r ₂ = 9.2724 d ₂ = 3.0628 r ₃ = 3.9176 _{(aspherical) d 3 = 7.0381 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -5.1468 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν ₃ = 60.00 Aspherical surface coefficient (first surface) a ₄ = 1.2663 × 10 ^-4 , a ₆ = -8.3747 × 10 ^-7 (third surface) a ₄ = -2.2037 × 10 ^-3 , a ₆ = -1.0353 × 10 ^-4 β _i -0.2700 -0.3600 -0.5400 d ₀ 21.9468 15.0000 8.0532 d ₅ 3.4362 4.1115 5.4621 Δds / f 0.6386 0.6386 0.6386 OH / d ₀ 0.3539 0.3884 0.4824 NA 0.03839 0.04500 0.05429 s ₁ = -5.3398, s ₂ = 0.1356, d ₁ / f ₂ = 1.2509, d ₃ / f ₂ = 1.1541

Example 9 f = 6.5386 r ₁ = 5.3394 (aspherical surface) d ₁ = 6.0761 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = -5.0082 d ₂ = 1.9907 r ₃ = ∞ (aperture) d ₃ = variable r _{4 = ∞ d 4 = 2.0000 n} 2 = 1.53714 ν 2 = 60.00 aspherical coefficients ^{_{a 4 = -1.2747 × 10 -3,}} a 6 = -1.7938 × 10 -4 β i -0.2700 -0.3600 -0.5400 d 0 28.1477 22.0935 16.0392 d ₃ 2.5660 3.1336 4.2682 Δds / f 0.6786 0.6786 0.6786 OH / d ₀ 0.2801 0.2644 0.2396 NA 0.01111 0.01285 0.01525 s ₁ = −0.0320, d ₁ /f=0.9293

Example 10 f = 7.6975 r ₁ = 11.6601 (aspherical surface) d ₁ = 6.3213 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = −4.5785 d ₂ = 2.6558 r ₃ = ∞ (aperture) d ₃ = variable r ₄ = ∞ d ₄ = 2.0000 n ₂ = 1.53714 ν ₂ = 60.00 Aspherical coefficient a ₄ = -1.7683 × 10 ^-3 , a ₆ = -1.6672 × 10 ^-4 β _i -0.2700 -0.3600 -0.5400 d ₀ 32.7130 25.5856 18.4583 _{d 3 4.4470 5.1399 6.5253 Δds / f} 0.5232 0.5232 0.5232 OH / d 0 0.2428 0.2302 0.2106 NA 0.01080 0.01285 0.01587 s 1 = -0.4361, d 1 /f=0.8212

Example 11 f = 7.4417 r ₁ = 8.7162 (aspherical surface) d ₁ = 4.1717 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = −5.2786 d ₂ = 2.8573 r ₃ = ∞ (aperture) d ₃ = variable r ₄ = ∞ d ₄ = 2.000 n ₂ = 1.53714 ν ₂ = 60.00 Aspherical coefficient a ₄ = -2.1865 × 10 ^-3 , a ₆ = -1.5966 × 10 ^-4 β _i -0.2700 -0.3600 -0.5400 d ₀ 33.0701 26.1796 19.2891 d ₃ 4.1216 4.7914 6.1309 Δds / f 0.5413 0.5413 0.5413 OH / d ₀ 0.2313 0.2193 0.1989 NA 0.01083 0.01285 0.01581 s ₁ = −0.2456, d ₁ / f = 0.5606

Example 12 f = 5.7375 r ₁ = 5.5571 (aspherical surface) d ₁ = 3.9366 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = -4.3607 d ₂ = 1.6695 r ₃ = ∞ (aperture) d ₃ = variable r _{4 = ∞ d 4 = 2.0000 n} 2 = 1.53714 ν 2 = 60.00 aspherical coefficients ^{_{a 4 = -4.1430 × 10 -3,}} a 6 = -3.3920 × 10 -4 β i -0.2699 -0.3599 -0.5398 d 0 25.2904 19.9768 14.6631 d ₃ 2.9794 3.4955 4.5279 Δds / f 0.5239 0.5239 0.5239 OH / d ₀ 0.3077 0.2914 0.2639 NA 0.02696 0.03213 0.03975 s ₁ = −0.1206, d ₁ / f = 0.6861

Example 13 f ₁ = −365.5117, f ₂ = 5.2423 r ₁ = 7.6870 (aspherical surface) d ₁ = 7.1916 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 5.1036 d ₂ = variable r ₃ = 2.4872 (non-spherical) _{spherical) d 3 = 4.5932 n 2 =} 1.48978 ν 2 = 57.66 r 4 = 31.2111 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 non Spherical coefficient (first surface) a ₄ = -2.8864 × 10 ^-5 , a ₆ = -3.2368 × 10 ^-6 (third surface) a ₄ = -4.2442 × 10 ^-3 , a ₆ = -5.6348 × 10 ^-4 _{β i -0.2700 -0.3600 -0.5400 f 7.4891 7.5923} 7.7343 d 0 15.0712 15.6172 18.7532 d 2 8.2562 4.7793 0.1450 d 5 2.7878 3.5004 4.9456 Δds / f 0.7240 0.7276 0.7323 OH / d 0 0.5156 0.3700 0.2054 NA 0.01125 0.01285 0.01508 s 1 = -4.9510, s ₂ = 1.1732, d ₁ / f ₂ = 1.3719, d ₃ / f ₂ = 0.8762

Example 14 f ₁ = 499.4373, f ₂ = 4.9689 r ₁ = 7.7111 (aspherical surface) d ₁ = 7.1060 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 5.5499 d ₂ = variable r ₃ = 2.1959 (aspherical surface) _{) d 3 = 3.7288 n 2 =} 1.48978 ν 2 = 57.66 r 4 = 9.9285 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 aspherical Coefficient (first surface) a ₄ = -2.1985 × 10 ^-4 , a ₆ = -4.0368 × 10 ^-7 (third surface) a ₄ = -3.0571 × 10 ^-3 , a ₆ = -1.4733 × 10 ^-3 β _i -0.2701 -0.3601 -0.5401 f 7.1836 7.1084 7.0705 d ₀ 14.2268 14.9350 12.0956 d ₂ 8.2462 4.5900 2.7178 d ₅ 2.6628 3.2827 4.5423 Δds / f 0.7183 0.7152 0.7136 OH / d ₀ 0.5440 0.3887 0.3178 NA 0.01115 0.01286 0.01513 s ₁ = -6.1359, s _{2 = 1.5680, d 1 / f} 2 = 1.4301, d 3 / f 2 = 0.7504

Example 15 f ₁ = 550.2785, f ₂ = 4.7440 r ₁ = 7.6988 (aspherical surface) d ₁ = 7.6743 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 5.3280 d ₂ = variable r ₃ = 2.0373 (aspherical surface) _{) d 3 = 3.4998 n 2 =} 1.48978 ν 2 = 57.66 r 4 = 7.1998 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 aspherical Coefficient (first surface) a ₄ = -2.0671 × 10 ^-4 , a ₆ = -1.4113 × 10 ^-6 (third surface) a ₄ = -3.8422 × 10 ^-3 , a ₆ = -1.9113 × 10 ^-3 β _i -0.2701 -0.3601 -0.5400 f 7.1086 7.0321 6.9857 d ₀ 12.6009 14.6784 13.4867 d ₂ 8.2172 4.2234 1.7529 d ₅ 2.5227 3.1351 4.3755 Δds / f 0.7322 0.7292 0.7274 OH / d ₀ 0.6123 0.3943 0.2845 NA 0.01115 0.01286 0.01513 s ₁ = -5.4947, s _{2 = 1.7893, d 1 / f} 2 = 1.6177, d 3 / f 2 = 0.7377

Example 16 f ₁ = 196.3132, f ₂ = 4.5903 r ₁ = 7.5053 (aspherical surface) d ₁ = 7.8013 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 5.3589 d ₂ = variable r ₃ = 1.9705 (aspherical surface) _{) d 3 = 3.2061 n 2 =} 1.48978 ν 2 = 57.66 r 4 = 7.4190 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 aspherical Coefficient (first surface) a ₄ = -1.9045 × 10 ^-4 , a ₆ = -3.4160 × 10 ^-6 (third surface) a ₄ = -4.7102 × 10 ^-3 , a ₆ = -1.9389 × 10 ^-3 β _i -0.2700 -0.3600 -0.5398 f 7.1338 6.9349 6.7908 d ₀ 11.5925 12.9463 12.4239 d ₂ 8.1528 4.5297 1.7726 d ₅ 2.4933 3.0680 4.2405 Δds / f 0.7381 0.7300 0.7237 OH / d ₀ 0.6669 0.4463 0.3082 NA 0.01110 0.01285 0.01520 s ₁ = -5.9933, s _{2 = 1.7233, d 1 / f} 2 = 1.6995, d 3 / f 2 = 0.6985

Example 17 f ₁ = -78.6255, f ₂ = 4.7345 r ₁ = 7.6856 (aspherical surface) d ₁ = 7.2735 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 4.4135 d ₂ = variable r ₃ = 2.3217 (non-spherical) _{spherical) d 3 = 3.3352 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -998.4045 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 aspherical coefficients (first ^{_{surface) a 4 = -1.6682 × 10 -4}} , a 6 = -7.0667 × 10 -7 ( third ^{_{surface) a 4 = -3.9154 × 10 -3}} , a 6 = -6.5277 × 10 - ⁴ β _i -0.2700 -0.3600 -0.5400 f 6.5331 6.8589 7.2461 d ₀ 11.4687 11.7341 12.5308 d ₂ 7.5452 4.8391 1.9389 d ₅ 3.2547 3.9796 5.4466 Δds / f 0.5727 0.5901 0.6088 OH / d ₀ 0.6778 0.4935 0.3072 NA 0.01117 0.01285 0.01510 s ₁ = -3.6977 , S ₂ = 0.9954, d ₁ / f ₂ = 1.5363, d ₃ / f ₂ = 0.7045

Example 18 f ₁ = -14.4705, f ₂ = 4.7131 r ₁ = 7.5911 (aspherical surface) d ₁ = 8.6741 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 2.2884 d ₂ = variable r ₃ = 3.1268 (non-spherical) _{spherical) d 3 = 5.8241 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -3.4187 d 4 = 1.1164 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 Aspheric coefficient (first surface) a ₄ = 1.6444 × 10 ^-5 , a ₆ = 8.4973 × 10 ^-6 (third surface) a ₄ = -1.3073 × 10 ^-3 , a ₆ = -5.4567 × 10 ^-4 β _{i -0.2700 -0.3600 f 6.8504 7.9348 d 0} 13.9000 13.9000 d 2 2.9947 1.6340 d 5 3.4903 4.8504 Δds / f 0.5706 0.5847 OH / d 0 0.5590 0.4168 NA 0.01241 0.01285 s 1 = -1.8631, s 2 = 0.0446, d 1 / f 2 = 1.8404, d ₃ / f ₂ = 1.2357

Example 19 f ₁ = 40.9433, f ₂ = 6.7259 r ₁ = 11.2682 (aspherical surface) d ₁ = 8.3671 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 19.4424 d ₂ = variable r ₃ = 3.7311 (aspherical surface) _{) d 3 = 5.4361 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -14.6571 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 non Spherical coefficient (first surface) a ₄ = −4.9203 × 10 ⁻⁵ , a ₆ = −9.2079 × 10 ⁻⁷ (third surface) a ₄ = −2.0822 × 10 ⁻³ , a ₆ = −1.5695 × 10 ⁻⁵ β _i -0.2700 -0.3600 f 14.1956 7.6683 d ₀ 12.8968 21.3575 d ₂ 17.4550 0.9423 d ₅ 3.6041 3.6041 Δds / f 0.9245 0.7203 OH / d ₀ 0.6036 0.2721 NA 0.00964 0.01285 s ₁ = 3.7570, s ₂ = 0.5942, d ₁ / f _{2 = 1.2440, d 3 / f 2} = 0.8082

Example 20 f ₁ = 31.5187, f ₂ = 5.5181 r ₁ = 12.7292 (aspherical surface) d ₁ = 5.4087 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 62.4307 d ₂ = variable r ₃ = 3.2633 (aspherical surface) _{) d 3 = 5.1275 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -7.6049 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 non Spherical coefficient (first surface) a ₄ = −4.2953 × 10 ⁻⁵ , a ₆ = −5.7661 × 10 ⁻⁷ (third surface) a ₄ = −2.2935 × 10 ⁻³ , a ₆ = −2.8137 × 10 ⁻⁴ β _i -0.2700 -0.3600 f 11.1248 5.7099 d ₀ 10.0780 15.6630 d ₂ 15.7768 0.9508 d ₅ 2.3224 2.3224 Δds / f 0.9443 0.7254 OH / d ₀ 0.7720 0.3709 NA 0.00964 0.01285 s ₁ = 1.5122, s ₂ = 0.3995, d ₁ / f ₂ = 1.0202, d ₃ / f ₂ = 0.9292

Example 21 f ₁ = -116.3746, f ₂ = 4.8143 r ₁ = 8.2608 (aspherical surface) d ₁ = 7.2125 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 5.1441 d ₂ = variable r ₃ = 2.6526 (non-spherical) _{spherical) d 3 = 3.3369 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -12.4457 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 aspherical coefficients (first ^{_{surface) a 4 = -1.2930 × 10 -4}} , a 6 = -7.3954 × 10 -7 ( third ^{_{surface) a 4 = -4.6460 × 10 -3}} , a 6 = -3.5078 × 10 - ⁴ β _i -0.2700 -0.3600 -0.5399 f 6.5072 6.7332 6.9950 d ₀ 11.3839 11.4486 12.0254 d ₂ 7.5177 4.6280 1.5144 d ₅ 3.4480 4.1243 5.4883 Δds / f 0.5401 0.5542 0.5693 OH / d ₀ 0.6830 0.5061 0.3204 NA 0.03841 0.04499 0.05424 s ₁ = -4.3010 , S ₂ = 0.6486, d ₁ / f ₂ = 1.4982, d ₃ / f ₂ = 0.6931

Example 22 f ₁ = −6.5847, f ₂ = 4.0748 r ₁ = −14.4672 (aspherical surface) d ₁ = 2.9861 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 4.4319 d ₂ = variable r ₃ = 1.9459 ( _{aspherical) d 3 = 2.1434 n 2 =} 1.48978 ν 2 = 57.66 r 4 = 49.6951 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 Aspheric coefficient (first surface) a ₄ = 1.5997 × 10 ⁻³ , a ₆ = −3.8182 × 10 ⁻⁵ (third surface) a ₄ = −1.3195 × 10 ⁻² , a ₆ = −3.5698 × 10 ⁻³ _{β i -0.2700 -0.3600 -0.5399 f 3.6503 4.4688} 5.4162 d 0 11.3760 11.5924 10.7403 d 2 4.4515 3.1052 2.0549 d 5 4.4424 5.5720 7.4741 f 1 / f 2 -1.6160 -1.6160 -1.6160 OH / d 0 0.6829 0.5035 0.3622 NA 0.01159 0.01285 0.01507 s _{1 = -0.5310, s 2 = 1.0815} , d 1 / f 2 = 0.7328, d 3 / f 2 = 0.5260

Example 23 f ₁ = −6.0385, f ₂ = 3.2540 r ₁ = −5.9977 (aspherical surface) d ₁ = 1.0342 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 6.1653 d ₂ = variable r ₃ = 1.5414 ( _{aspherical) d 3 = 2.5205 n 2 =} 1.48978 ν 2 = 57.66 r 4 = 21.7049 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 Aspheric coefficient (first surface) a ₄ = 6.8426 × 10 ⁻³ , a ₆ = −2.9638 × 10 ⁻⁴ (third surface) a ₄ = −2.0665 × 10 ⁻² , a ₆ = −1.1389 × 10 ⁻² _{β i -0.2700 -0.3600 -0.5400 f 3.2224 3.7961} 4.7161 d 0 11.5433 11.2177 11.1138 d 2 3.0951 2.1736 1.1639 d 5 2.7102 3.5159 5.1918 f 1 / f 2 -1.8557 -1.8557 -1.8557 OH / d 0 0.6707 0.5217 0.3510 NA 0.01136 0.01285 0.01447 s _{1 = 0.0138, s 2 = 1.1529} , d 1 / f 2 = 0.3178, d 3 / f 2 = 0.7746

Example 24 f ₁ = −5.3232, f ₂ = 3.0432 r ₁ = −7.0696 (aspherical surface) d ₁ = 3.5889 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 4.8199 d ₂ = variable r ₃ = 1.2786 ( _{aspherical) d 3 = 2.3864 n 2 =} 1.48978 ν 2 = 57.66 r 4 = 5.0616 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 Aspherical surface coefficient (first surface) a ₄ = 3.7496 × 10 ⁻³ , a ₆ = −1.2322 × 10 ⁻⁴ (third surface) a ₄ = −2.6423 × 10 ⁻² , a ₆ = −1.8348 × 10 ⁻² β _i -0.2700 -0.3600 f 3.1041 3.7425 d ₀ 10.3000 10.3159 d ₂ 2.3864 1.4963 d ₅ 2.9245 3.7985 f ₁ / f ₂ -1.7492 -1.7492 OH / d ₀ 0.7550 0.5654 NA 0.01162 0.01285 s ₁ = -0.1892, s ₂ = 1.6760, d ₁ / f ₂ = 1.1793, d ₃ / f ₂ = 0.5587

Example 25 f ₁ = -22.2683, f ₂ = 4.2349 r ₁ = -18.3803 (aspherical surface) d ₁ = 2.3528 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 27.9511 d ₂ = variable r ₃ = 2.6237 ( _{aspherical) d 3 = 3.1388 n 2 =} 1.48978 ν 2 = 57.66 r 4 = -6.0081 d 4 = 0.1000 r 5 = ∞ ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 aspherical coefficients (first ^{_{surface) a 4 = 4.0077 × 10 -4}} , a 6 = -6.5728 × 10 -6 ( third ^{_{surface) a 4 = -7.7661 × 10 -3}} , a 6 = -1.4288 × 10 - ³ β _i -0.2700 -0.3599 -0.5386 f 3.6487 3.9822 4.6218 d ₀ 9.8168 9.1188 10.0000 d ₂ 6.1478 3.9839 0.7062 d ₅ 2.8471 3.3588 4.5363 f ₁ / f ₂ -5.2583 -5.2583 -5.2583 OH / d ₀ 0.7937 0.6405 0.3898 NA 0.03776 0.04499 0.05407 s ₁ = 0.2066, s ₂ = 0.3921, d ₁ / f ₂ = 0.5556, d ₃ / f ₂ = 0.7412

Example 26 f ₁ = -5.9971 r ₁ = 13.8270 (aspheric surface) d ₁ = 5.3812 n ₁ = 1.48978 ν ₁ = 57.66 r ₂ = 2.1126 d ₂ = 0.9163 r ₃ = variable d ₃ = 5.0422 n ₂ = 1.59995 ν ₂ = 60.70 r ₄ = variable _{d 4 = 0.1000 r 5 = ∞} ( stop) d ₅ = variable _{r 6 = ∞ d 6 = 2.0000} n 3 = 1.53714 ν 3 = 60.00 aspherical coefficients a ₄ = 2.4935 × 10 ^{- 4} , a ₆ = -7.1236 x 10 ^-6 β _i -0.2700 -0.3600 -0.5400 f 6.1966 6.2060 6.2293 f ₂ 4.1922 4.1950 4.2019 d ₀ 20.7959 15.0918 9.4074 d ₅ 6.6925 7.2664 8.4280 r ₃ 3.7683 3.7720 3.7813 r ₄ -3.7683 -3.7720- 3.7813 Δds / f -0.0200 -0.0205 -0.0219 OH / d ₀ 0.3740 0.3866 0.4136 NA 0.01033 0.01285 0.01698 d ₁ / f ₂ 1.2836 1.2828 1.2807 d ₃ / f ₂ 1.2027 1.2020 1.2000 s ₁ = -1.3607, s ₂ = 0

Example 27 f ₁ = -14.3370 r ₁ = 3.8653 (aspheric surface) d ₁ = 0.6712 n ₁ = 1.48978 v ₁ = 57.66 r ₂ = 2.3507 d ₂ = 0.3005 r ₃ = variable d ₃ = 3.6239 n ₂ = 1.59995 ν ₂ = 60.70 r ₄ = variable _{d 4 = 0.1000 r 5 = ∞} ( _{stop) d 5 = 4.1400 r 6 =} ∞ d 6 = 2.0000 n 3 = 1.53714 ν 3 = 60.00 aspherical coefficients a ₄ = 7.0445 × 10 ^{- 4} , a ₆ = -2.4055 × 10 ^-3 β _i -0.2699 -0.3599 -0.5399 f 5.1934 4.8719 4.3399 f ₂ 4.0369 3.8547 3.5400 d ₀ 22.0000 15.9734 9.9318 r ₃ 4.0265 3.7977 3.3983 r ₄ -4.0265 -3.7977 -3.3983 Δds / f 0.2227 _{0.2436 0.2866 OH / d 0 0.3536 0.3644} 0.3888 NA 0.00964 0.01285 0.01928 d 1 / f 2 0.1663 0.1741 0.1896 d 3 / f 2 0.8977 0.9401 1.0237 s 1 = -4.1040, s 2 = 0

Example 28 f ₁ = -54.6534 r ₁ = 2.5333 (aspherical surface) d ₁ = 1.5760 n ₁ = 1.48978 v ₁ = 57.66 r ₂ = 1.8410 d ₂ = 0.6727 r ₃ = variable d ₃ = 4.4243 n ₂ = 1.59995 ν ₂ = 60.70 r ₄ = variable d ₄ = 0.1000 r ₅ = ∞ (aperture) d ₅ = 5.1173 r ₆ = ∞ d ₆ = 2.0000 n ₃ = 1.53714 ν ₃ = 60.00 Aspherical coefficient a ₄ = -1.1233 × 10 _{^{-3, a 6 = -4.8274 × 10}} -4 β i -0.2700 -0.3600 -0.5400 f 7.3537 6.8191 5.9632 f 2 5.4286 5.0805 4.5109 d 0 31.2360 22.2639 13.2586 r 3 5.5381 5.1056 4.3898 r 4 -5.5381 -5.1056 -4.3898 Δds / f _{0.3972 0.4188 0.4637 OH / d 0 0.2500} 0.2622 0.2918 NA 0.00964 0.01285 0.01929 d 1 / f 2 0.2903 0.3102 0.3494 d 3 / f 2 0.8150 0.8708 0.9808 s 1 = -6.3180, s 2 = 0

Example 29 f ₁ = −8.4743 r ₁ = 7.5770 (aspheric surface) d ₁ = 5.4132 n ₁ = 1.48978 v ₁ = 57.66 r ₂ = 2.0517 d ₂ = 0.5500 r ₃ = variable d ₃ = 4.9785 n ₂ = 1.59995 v ₂ = 60.70 r ₄ = variable d ₄ = 0.1000 r ₅ = ∞ (aperture) d ₅ = variable r ₆ = ∞ d ₆ = 2.0000 n ₃ = 1.53714 v ₃ = 60.00 Aspherical coefficient a ₄ = -1.2556 × 10 ^-4 , a ₆ = 2.0694 × 10 ^-5 β _i -0.2700 -0.3600 -0.5400 f 6.8759 6.9446 6.7388 f ₂ 4.0871 4.1072 4.0466 d ₀ 23.8976 17.7945 10.7666 d ₅ 5.7682 6.4868 7.4009 r ₃ 3.6499 3.6772 3.5947 r ₄ -3.6499 -3.6772- 3.5947 Δds / f 0.2119 0.2386 0.2487 OH / d 0 0.3253 0.3280 0.3615 NA 0.03708 0.04500 0.06080 d 1 / f 2 1.3245 1.3180 1.3377 d 3 / f 2 1.2181 1.2122 1.2303 s 1 = -1.7427, s 2 = 0 However r _1, r ₂ , ... are the radii of curvature of the respective surfaces of the lens, d
_.. , D ₂ ,...
₁ , n ₂ ,... Are the refractive indices of each lens, ν ₁ , ν ₂ ,.
Is the Abbe number of each lens, and d ₀ is the distance from the object to the first surface of the lens. In the data, d ₀ , d _5, etc. indicate values at each magnification (β _i ) of the optical system.

The first to eighth embodiments are an optical system having a configuration as shown in FIG. 14, in which, in order from the object side, a front lens group having a convex surface facing the object side and a positive lens having a convex surface facing the object side. It consists of a rear group and an aperture. That is, this is the first configuration of the reading optical system of the present invention. Also at least one
The surface is aspherical, and when reading information recording media having different recording densities, as the reading optical system changes from a reading optical system having a relatively small absolute value of the imaging magnification to a reading optical system having a large absolute value of the imaging magnification, This is a reading optical system that increases the distance between the information recording medium and the front group and reduces the distance between the rear group and the image sensor. A red light-emitting diode (emission wavelength range of 610 to 700 nm and center wavelength of 660 nm) is used as a light source.

FIG. 14 is a sectional view of the second embodiment, and the other embodiments 1 and 3 to 8 have the same configuration. The aberration situation in the second embodiment is as shown in FIG. 23. In the figure, the upper part has a magnification of −0.2764, and the middle part has a magnification of −0.366.
7. The lower part shows a state where the magnification is -0.5447.

Embodiments 9 to 12 show the second configuration of the optical system of the present invention, which comprises, in order from the object side, a front group of a biconvex positive lens and an aperture, and at least one surface is non-convex. The optical system is a spherical surface. In these embodiments, when reading information recording media having different recording densities, the information recording medium is changed from an optical system having a relatively small absolute value of the imaging magnification to an optical system having a large absolute value of the imaging magnification. From lens 1
The lens is moved so that the distance from the surface increases and the distance from the second lens surface to the imaging element surface decreases.

The twelfth embodiment among these embodiments is the same as the one shown in FIG.
As shown in FIG. 9, the ninth to eleventh embodiments of the other embodiments have a similar configuration to the twelfth embodiment. Note that the aberration states in these embodiments have the same tendency as in the second embodiment, and are corrected well.

The thirteenth to twenty-first embodiments are the third configuration of the reading optical system of the present invention, in which the front group of the meniscus lens having the convex surface facing the object side and the convex surface facing the object side are arranged in order from the object side. This is an optical system having at least one aspherical surface with a two-group configuration including a rear group of a positive lens and an aperture. This optical system, when reading information recording media with different recording densities, to change from an optical system with a relatively small absolute value of the imaging magnification to an optical system with a large absolute value of the imaging magnification, The rear group is moved so as to reduce the lens interval.

Of these embodiments, the fifteenth embodiment is shown in FIG.
This is the configuration shown in FIG. Examples 13, 14, 1
Reference numeral 6 denotes a configuration similar to that of the fifteenth embodiment.

Embodiment 18 is as shown in FIG. 17, and Embodiment 20 is as shown in FIG. Embodiments 17, 19, and 21 have configurations similar to Embodiments 18 and 20.

The aberration states of the thirteenth to twenty-first embodiments are all as good as those of the first embodiment, and these embodiments are also reading optical systems having good optical performance.

Embodiments 22 to 25 are the fourth construction of the reading optical system according to the present invention. In the order from the object side, the front group of the biconcave lens, the rear group of the positive lens whose convex surface faces the object side, and the stop are arranged in that order. And an optical system having at least one aspheric surface. In these embodiments, when reading information recording media having different recording densities, an optical system having a relatively small absolute value of the imaging magnification is changed from an optical system having a relatively large absolute value of the imaging magnification to an absolute value of the imaging magnification. The change to the optical system having a relatively large value is changed by moving the front group and the rear group so as to reduce the distance between the two lenses.

Of these embodiments, embodiment 22 is the same as that of FIG.
The configuration shown in FIG. 9 is the same as that of the twenty-second embodiment. Examples 24 and 25 are as shown in FIGS. 20 and 21, respectively. The aberration conditions in these embodiments are the same as those in the first embodiment, and the aberrations are satisfactorily corrected.

Embodiments 26 to 29 relate to the fifth configuration of the reading optical system of the present invention. As in Embodiment 27 shown in FIG. 22, a meniscus having convex surfaces facing the object side is arranged in order from the object side. The optical system has a two-group, two-element configuration including a front lens group, a biconvex positive lens, and a stop. The biconvex lens in the rear group of these examples is made of a transparent elastic body.

In these embodiments, in order to read information having different recording densities, the curvature of the transparent elastic body is changed to change the imaging magnification. Incidentally, (A), (B), (C) or (A), (B) in the sectional views of each embodiment correspond to each magnification in the data.

In the present invention, in addition to those described in the claims, those described in the following items can also achieve the object.

(1) An information reproducing apparatus provided with an optical system for reading an information recording medium on which predetermined information is recorded, wherein the optical system is composed of a front group and a rear group in order from the information recording medium side. A first lens holding member that holds the front group, a second lens holding member that holds the rear group, and a photographing unit holding member that holds the image sensor at a predetermined position in a predetermined direction. A first lens holding member provided at a first connection portion between the first lens holding member and the second lens holding member and a second connection portion between the second lens holding member and the photographing portion holding member; An information reproducing apparatus comprising first and second moving mechanisms for moving a member and a second lens holder to a predetermined position along an optical axis.

(2) An apparatus for reading an information recording medium on which predetermined information is recorded by forming an image on an image sensor by an optical system for reading the information recording medium, wherein the reading optical system is arranged in order from the information recording medium side to the front group. And an optical unit for fixedly fixing the front group and the image pickup device at a predetermined position in a predetermined direction, and a lens holding member for holding the rear group. An information reproducing apparatus comprising: a connection mechanism between a member and the optical unit; and a moving mechanism for moving the lens holding member and the optical unit along the optical axis to a predetermined position on the optical axis at a predetermined position.

(3) An apparatus for reading an information recording medium on which predetermined information is recorded by forming an image on an image pickup device by a reading optical system, wherein the reading optical system sequentially includes a front group and a rear group from the information recording medium side. An optical unit for integrally fixing the image pickup device at a predetermined position in a predetermined direction, and a lens holding member for holding the other group; An information reproducing apparatus, wherein a lens held by a lens holding member is formed of a transparent elastic body, and the lens holding member has a lens pressing mechanism for pressing a side surface of the transparent elastic lens.

(4) An information reproducing apparatus which reads an information recording medium on which predetermined information is recorded and forms an image on the image sensor by a reading optical system, and holds the image sensor at a predetermined position in a predetermined direction. A lens holding member for holding a reading optical system, a tip member arranged to keep a constant distance between the information recording medium, the information recording medium, and a tip of the information reproducing apparatus; A moving member provided at a connecting portion with the portion holding member, and a moving member provided at a connecting portion between the distal end member and the lens holding member, wherein the distal end member and the lens holding member are at predetermined positions. An information reproducing apparatus comprising a moving mechanism movable along an optical axis.

(5) In the apparatus according to claim 1 or (4), when reading from a recording medium having a low recording density to a recording medium having a high recording density, the reading optical system is used. An information reproducing apparatus, comprising: a moving mechanism configured to move the image pickup element so as to increase a distance between the image pickup element and the image pickup element.

(6) In the apparatus described in the above item (1) or (2), when reading from a recording medium having a low recording density to a recording medium having a high recording density, the front optical system and the rear optical system of the reading optical system are used. An information reproducing apparatus, comprising: a moving mechanism for reducing the distance between the groups and increasing the distance between the rear group and the image sensor.

(7) In the apparatus described in the above (3),
A moving member for holding the optical unit and the lens holding member, and when reading the information recording medium from a low recording density to a high recording density, the lens pressing mechanism is transparent in conjunction with the movement of the moving member. An information reproducing apparatus characterized in that a side surface of a lens group formed of an elastic body is pressed toward an optical axis.

(8) An information reproducing apparatus for reading an information recording medium according to claim 2, wherein the information reproducing apparatus includes an index which is the same as or corresponds to the index of the information recording medium. apparatus.

(9) An information reproducing apparatus for reading an information recording medium according to claim 2, wherein an index for identifying the information recording medium and a mark for designating the index are provided. An information reproducing apparatus characterized in that one of them is displayed on a moving member connected to the information reproducing apparatus, and the other is displayed on an exterior of the information reproducing apparatus.

(10) Claim 1 of the claims or the above (1), (2), (3), (4), (5),
(6) In the information reproducing apparatus described in (7), (8) or (9), when reading the information recording medium, the moving member, the lens holding member, the photographing unit holding member, or the optical member An information reproducing apparatus characterized in that an index for discriminating an information recording medium is provided in one of the units.

(11) In the information reproducing apparatus according to claim 1 or (4), (5), (9) or (11), the information reading optical system is an information recording medium (object). ), In order from the side, the first lens is a lens having a convex surface facing the object side, the second lens is a positive lens having a convex surface facing the object side, and the diaphragm is a two-group configuration including at least one aspheric surface. When reading information recording media having different recording densities, the distance between the first lens and the imaging element is increased and the distance between the information recording medium and the second lens is reduced so that the imaging magnification is reduced. An information recording / reproducing apparatus characterized by changing from an optical system having a relatively small absolute value to an optical system having a relatively large absolute value of the imaging magnification so as to satisfy the following condition. (1) −0.8 <β _i <−0.1 (2) −0.6 <Δds / f <1.5 (3) 0.05 <OH / d ₀ <1.60 (4) 005 <NA <0.08

(12) An information reading optical system or an information reproducing apparatus according to claim 3, wherein the optical system satisfies the following conditions: . (5) 0.5 <| S ₁ | <12 (6) −0.5 <S ₂ <2.0 (7) 0.3 <d ₁ / d ₂ <3.0 (8) 0.3 < d ₃ / f ₂ <2.5

(13) In a reading optical system for forming an image of an information recording medium on which predetermined information is recorded on an image pickup device, the optical system is composed of a biconvex lens and an aperture in order from the object side. When reading information recording media having different recording densities with one surface being aspherical, the reading optical system having a relatively small absolute value of the imaging magnification changes from a reading optical system having a relatively large absolute value of the imaging magnification to a reading optical system having a large absolute value of the imaging magnification. The distance between the recording medium and the first surface of the lens is increased and the distance between the second surface of the lens and the image sensor is decreased, and the following conditions (1), (2), (3), and (4) are satisfied. Satisfactory reading optical system. (1) −0.8 <β _i <−0.1 (2) −0.6 <Δds / f <1.5 (3) 0.05 <OH / d ₀ <1.60 (4) 005 <NA <0.08

(14) In the apparatus described in claim 1 or in (4), (5), (8) or (9), the optical system is biconvex in order from the object side. A reading optical system having a relatively small absolute value of the imaging magnification when reading information recording media having different recording densities. As the reading optical system becomes larger, the distance between the recording medium and the first lens surface is increased, and the relationship between the second lens surface and the imaging device is reduced, and the following conditions (1) and (2) are satisfied. A reading optical system satisfying (3) and (4). (1) −0.8 <β _i <−0.1 (2) −0.6 <Δds / f <1.5 (3) 0.05 <OH / d ₀ <1.60 (4) 005 <NA <0.08

(15) In the reading optical system described in the above item (13) or the information reproducing apparatus described in the above item (14), the optical system is different from the condition (5) in that the condition (5-
A reading optical system or information reproducing apparatus that satisfies 1) and further satisfies the condition (9). (5-1) −0.8 <S ₁ <0.4

(16) In a reading optical system for forming an image of an information recording medium on which predetermined information is recorded on an image pickup device, the optical system may include a meniscus having a convex surface facing the object side in order from the object side. A reading optical system comprising a lens, a positive lens having a convex surface facing the object side, and an aperture, at least one surface of which is aspheric, and having a relatively small absolute value of the imaging magnification when reading information recording media having different recording densities. As the reading optical system has a larger absolute value of the imaging magnification from the system, the distance between the meniscus lens and the lens is moved to be smaller, and the following conditions (1), (2), (3) and (4) are set. A reading optical system that satisfies). (1) −0.8 <β _i <−0.1 (2) −0.6 <Δds / f <1.5 (3) 0.05 <OH / d ₀ <1.60 (4) 005 <NA <0.08

(17) Claim 1 of the claims or the above (1), (2), (4), (5), (6),
(8) In the information reproducing apparatus according to (9), the optical system includes, in order from the object side, a stop composed of a meniscus lens having a convex surface facing the object side and a positive lens having a convex surface facing the object side. A two-group, two-element configuration, at least one surface of which is aspheric, and a reading optical system having a relatively small absolute value of the imaging magnification when reading information recording media having different recording densities has a large absolute value of the imaging magnification. As the reading optical system becomes, the distance between the meniscus lens and the positive lens is moved so as to be smaller, and the following conditions (1), (2), (3), and (4) are satisfied.
Information playback device that satisfies the requirements. (1) −0.8 <β _i <−0.1 (2) −0.6 <Δds / f <1.5 (3) 0.05 <OH / d ₀ <1.60 (4) 005 <NA <0.08

(18) In the reading optical system described in (16) or the information reproducing apparatus described in (17), the conditions (5-2), (6-1), and (7) are satisfied. ,
A reading optical system or information reproducing device satisfying (8). (5-2) 1.2 <| S ₁ | <12 (6-1) −0.5 <S ₂ <4.2 (7) 0.3 <d ₁ / f ₂ <3.0 (8) 0.3 <d ₃ / f ₂ <2.5

(19) In a reading optical system for forming an image of an information recording medium on which predetermined information is recorded on an image pickup device, the optical system may turn a biconcave lens and a convex surface toward the object side in order from the object side. An image is formed from a reading optical system having a relatively small absolute value of an imaging magnification when reading information recording media having different recording densities in a two-group, two-lens configuration including a positive lens and an aperture. As the reading optical system has a larger absolute value of magnification, the distance between the biconcave lens and the positive lens is moved to be smaller, and the following condition (1) is satisfied.
A reading optical system satisfying (9), (3) and (4). (1) −0.8 <β _i <−0.1 (9) −10.6 <f ₁ / f ₂ <−0.5 (3) 0.05 <OH / d ₀ <1.60 (4) ) 0.005 <NA <0.08

(20) Claim 1 of the claims or the above (1), (2), (4), (5), (6),
(8) In the information reproducing apparatus described in (9), the optical system includes, in order from the object side, a two-group, two-element system including a biconcave lens on the object side, a positive lens with the convex surface facing the object side, and an aperture. When reading information recording media having at least one aspherical surface and different recording densities, the reading optical system changes from a reading optical system having a relatively small absolute value of the imaging magnification to a reading optical system having a relatively large absolute value of the imaging magnification. An information reproducing apparatus which moves so as to reduce the distance between the biconcave lens and the positive lens according to the above, and satisfies the following conditions (1), (9), (3) and (4). (1) −0.8 <β _i <−0.1 (9) −10.6 <f ₁ / f ₂ <−0.5 (3) 0.05 <OH / d ₀ <1.60 (4) ) 0.005 <NA <0.08

(21) The reading optical system described in (19) or the information reproducing device described in (20), wherein the reading optical system or the information reproducing device satisfies the following conditions. _{(5-3) -0.8 <S 1 <} 0.6 (6-1) -0.5 <S 2 <4.0 (7-1) 0.15 <d 1 / f 2 <2.50 (8) 0.3 <d ₃ / f ₂ <2.5

(22) An optical system for reading an optical image of an information recording medium on which predetermined information is recorded, wherein the optical system comprises a meniscus lens having a convex surface facing the object side, a biconvex positive lens, and a stop. In a two-group, two-lens configuration, the biconvex lens is formed of a rubber-like transparent elastic body, and the curvature of the rubber-like transparent elastic body is variable when reading information recording media having different recording densities. Reading optics.

(23) Claim 1 of the claims or (3), (4), (5), (7), (8),
(9) The information reproducing apparatus according to (10), wherein the optical system has a two-group configuration including a meniscus lens having a convex surface facing the object side, a biconvex lens, and a diaphragm, wherein the biconvex lens is a rubber. An information reproducing apparatus characterized in that a curvature of a biconvex lens is variable when reading information recording media having different recording densities and formed of a transparent elastic body having a shape.

(24) In the reading optical system described in the above (22) or the information reproducing apparatus described in the above (23), the optical system may satisfy the following conditions (1), (2),
A reading optical system or information reproducing device satisfying (3) and (4). (1) −0.8 <β _i <−0.1 (2) −0.6 <Δds / f <1.5 (3) 0.05 <OH / d ₀ <1.60 (4) 005 <NA <0.08

[0160]

The information reproducing apparatus of the present invention can read different types of information recording media having different recording densities in a predetermined size. Further, the recording medium of the present invention can easily determine the type such as the recording density. Further, the reading optical system used in the information reproducing apparatus of the present invention enables reading at the above-mentioned predetermined size by a simple method.

[Brief description of the drawings]

FIG. 1 is a sectional view of an information reproducing apparatus having a first configuration according to the present invention.

FIG. 2 is a sectional view of an information reproducing apparatus having a second configuration according to the present invention;

FIG. 3 is a sectional view of an information reproducing apparatus having a third configuration according to the present invention;

FIG. 4 is a sectional view of an information reproducing apparatus according to a fourth configuration of the present invention.

FIG. 5 is a sectional view showing a moving mechanism of the information reproducing apparatus of the present invention.

FIG. 6 is a diagram showing a configuration of a cam groove used in the moving mechanism.

FIG. 7 is a sectional view showing another moving mechanism of the information reproducing apparatus of the present invention.

FIG. 8 is a diagram showing a configuration of a cam groove of the moving mechanism.

FIG. 9 is a sectional view of still another moving mechanism of the information reproducing apparatus of the present invention.

FIG. 10 is a sectional view of an information reproducing apparatus having a pressing mechanism according to a fourth configuration of the present invention.

FIG. 11 shows an information recording medium of the present invention.

FIG. 12 is a diagram showing a display example of the outer surface of the information reproducing apparatus of the present invention.

FIG. 13 is a diagram showing another display example of the outer surface of the information reproducing apparatus of the present invention.

FIG. 14 is a sectional view of Embodiment 2 of the reading optical system of the present invention.

FIG. 15 is a sectional view of Embodiment 12 of the reading optical system of the present invention.

FIG. 16 is a sectional view of Embodiment 16 of the reading optical system of the present invention.

FIG. 17 is a sectional view of Embodiment 18 of the reading optical system of the present invention.

FIG. 18 is a sectional view of Embodiment 20 of the reading optical system of the present invention.

FIG. 19 is a sectional view of Embodiment 22 of the reading optical system of the present invention.

FIG. 20 is a sectional view of Embodiment 24 of the reading optical system of the present invention.

FIG. 21 is a sectional view of Embodiment 25 of the reading optical system of the present invention.

FIG. 22 is a sectional view of Embodiment 27 of the reading optical system of the present invention.

FIG. 23 is an aberration curve diagram of the reading optical system according to the second embodiment of the present invention.

FIG. 24 is a diagram showing a state of an image on an image sensor in the information reproducing apparatus.

FIG. 25 is a sectional view of a conventional information reproducing apparatus.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location G06K 7/015 G02B 7/04 Z

Claims (3)

[Claims] 1. An information reproducing apparatus comprising: an information recording medium on which predetermined information is recorded; and a reading optical system for forming an image of the recording medium on an image sensor, wherein the image sensor is located at a predetermined position. A photographing unit holding member for holding in a predetermined direction, a lens holding member for holding the reading optical system,
A tip member arranged to keep the distance between the information recording medium and the tip of the information recording device constant, a connection portion between the tip member and the lens holding member, the lens holding member, and the photographing portion holding member An information reproducing apparatus provided with first and second moving mechanisms disposed at a connection portion between the first and second moving members to move a tip member, a lens holding member, and a photographing portion holding member at predetermined positions along an optical axis. 2. An information recording medium on which predetermined information is recorded, wherein an index for discriminating the type of information recording density is provided at or near the information recording medium. 3. A reading optical system for forming an image of an information recording medium on which predetermined information is recorded on an image pickup device, wherein the optical system includes a lens having a convex surface facing the object side in order from the object side. It consists of a first lens unit, a second lens unit having a convex surface facing the object side, a second lens unit, and a stop. The two units consist of two lenses. At least one surface is an aspherical surface. As the reading optical system has a relatively small absolute value of the image magnification and becomes a reading optical system having a large absolute value of the imaging magnification, the distance between the recording medium and the first group is reduced to reduce the distance between the second group and the image sensor. Move to increase the distance between
A reading optical system satisfying the following conditions (1), (2), (3) and (4). (1) −0.8 <β _i <−0.1 (2) −0.6 <Δds / f <1.5 (3) 0.05 <OH / d ₀ <1.60 (4) 005 <NA <0.08, where β _i is the imaging magnification of the i-th state, f is the focal length of the entire reading optical system, Δds is the distance from the principal point position of the reading optical system to the stop, and OH is the height of the object. Here, d ₀ is the distance from the information recording medium to the first group object-side surface.