JP2008052101A - Cemented optical element and optical apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a cemented optical element which can suppress shape change of an optical functional face due to change of environment such as temperature and humidity. <P>SOLUTION: In the cemented optical element which is constituted by cementing a resin submaterial 2a consisting of an optical material onto the optical functional face s1 of a glass base material 1a consisting of the optical material, a correction member 2b for suppressing deformation of a cemented optical element main body part due to material difference between the glass base material 1a and the resin submaterial 2a is cemented onto at least one optical functional face of the glass base material 1a or the resin submaterial 2a or onto a face ranging thereto. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cemented optical element including a cemented lens or a compound lens obtained by cementing or integrating at least two parts made of different materials, and an optical apparatus using the same.

  Specific examples of this type of bonded optical element include those in which two glass lenses of different materials are bonded with an adhesive, and those in which an energy curable resin is formed on the optical surface of the glass lens. It is done.

  In general, an optical element undergoes some shape change due to an environmental change such as a temperature change or a humidity change (hereinafter, a deformation generated in the optical element due to the environmental change is referred to as an “environmental deformation”). Here, if the environmental deformation of the optical element is non-similar, the geometric shape such as the radius of curvature of each optical functional surface greatly changes from the design value, and the optical system using the optical element should be originally exhibited. Optical function is distorted. Therefore, the optical element is required to be deformed similarly to the environmental change.

  Therefore, how the geometrical shape of the optical element changes due to environmental changes depends on variables representing the surrounding environment such as temperature and humidity (hereinafter referred to as “environment variables”). Spatial distribution of state variables such as temperature and water absorption, and material property values such as the thermal expansion coefficient and humidity expansion coefficient of the optical element itself, defined as the rate of change of the length or volume of the optical element according to the state variable Depends on the distribution.

That is, the spatial distribution of state variables and material property values is important, and if at least one of the respective spatial distributions is non-uniform, the optical element may be deformed unsimilarly.
In addition, even if the optical element itself does not have the nonuniformity of the spatial distribution of the state variables and material property values as described above, when the optical element itself is strongly fixed to the lens frame or the like, There is a possibility that the optical element may be deformed in a non-similar manner due to environmental changes.

Many studies have been made in the past in connection with such environmental deformation of optical elements.
For example, Patent Document 1 relates to a support structure for an optical element. The optical element is supported between the optical element and the support member via an elastic member that is softer than both components, and the elastic member is relatively deformed. Thus, it is disclosed that the generation of distortion on the optical surface of the optical element is suppressed by reducing the external force applied to the optical element.

  Patent Document 2 also relates to a support structure for an optical element, and an external force applied to the optical element by allowing relative movement of both in a direction other than the optical axis direction by a base member provided between the optical element and the support member. It is disclosed that the occurrence of distortion on the optical functional surface of the optical element is suppressed by reducing the above.

These Patent Documents 1 and 2 are mainly based on the design concept of improving the connection relationship between the optical element and the support member and making the deformation of the optical element independent of the deformation of the support member.
Patent Document 3 relates to the structure of a lens unit having a plurality of lenses made of different materials, and bonds lenses having greatly different expansion coefficients due to temperature and humidity, and fits and holds the lens having the smaller expansion coefficient with the lens frame. By doing this, it is disclosed that the dimensional change of the lens due to the temperature and humidity change is suppressed. This is based on the design concept of paying attention to the clearance between each lens outer diameter and lens frame hole inner diameter, evaluating this from the viewpoint of the expansion coefficient due to temperature and humidity, and determining which lens should be fixed to the lens frame.

  Patent Document 4 relates to a thermal deformation suppression mechanism of a reflective mirror, and detects a non-uniform heat distribution using a thermoelectric element, a photoelectric element, and a pyroelectric element, and distorts the piezoelectric element by an electromotive force at this time. The point which suppresses the thermal deformation of a reflective mirror by being disclosed is disclosed. This is mainly based on the design concept of controlling the deformation of the reflecting mirror in real time using various electrical sensors.

Further, Patent Document 5 discloses a point in which a mechanical property of an adhesive, a radius of curvature of a joint surface, and the like are limited with respect to a joint resin lens made of two materials having different thermal expansion coefficients. This is based on a design philosophy that a soft adhesive is selected as an adhesive interposed between two resin lenses, and further, the deformation of the two resin lenses is made independent by limiting the curvature of the optical function surface. .
JP 2001-343576 A JP-A-10-186196 JP-A-8-234070 JP 2002-100551 A Japanese Patent No. 3068641

  However, all of the conventional examples described above deal with the environmental deformation of the optical element. However, the environmental deformation of the cemented optical element does not necessarily provide a general and practical solution.

  For example, Patent Document 1 and Patent Document 2 hold when the optical element to be supported is made of a uniform material, but the spatial distribution of the material inherent in the optical element itself, such as a cemented lens or a compound lens, that is, For a bonded optical element that causes non-similar environmental deformation due to the spatial distribution of the thermal expansion coefficient and the humidity expansion coefficient, the effect may not be sufficiently exhibited.

  In the case of Patent Document 3, a certain effect can be expected from the viewpoint of suppressing environmental deformation as a whole lens unit including a lens and a lens frame, but a cemented optical element (junction lens) as a component of the lens unit alone. As for non-similar environmental deformations that occur in Japan, it is not necessarily sufficient.

  Further, in Patent Document 4, if a thermoelectric element, a photoelectric element, and the like can be appropriately designed and arranged, it can be an effective solution to the thermal deformation problem of the entire optical element including the bonded optical element, but the mechanism is complicated, and the cost and From the viewpoint of space saving, it is difficult to mount on consumer devices and small lens systems.

  Furthermore, Patent Document 5 is effective from the viewpoint of suppressing temperature deformation of the cemented lens, but can also be disadvantageous in terms of rigidity of the cemented optical element and assembly accuracy. In addition, the restriction on the radius of curvature of the joint surface necessary for demonstrating this technique narrows the degree of freedom in optical design, and it can be said that the versatility is poor.

  As described above, various studies have been made on the environmental deformation of optical elements. In particular, the optical functional surface due to environmental changes that inevitably occur during normal use of cemented optical elements such as cemented lenses or compound lenses. There has been no disclosure of practically effective measures for shape change (environmental deformation), optical function failure, and countermeasures.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a bonded optical element capable of suppressing a change in shape of an optical functional surface due to an environmental change such as temperature and humidity, and a bonding optical element thereof. It is to provide an optical device used.

In order to achieve the object, the invention according to claim 1
A main body part in which a secondary material made of an optical material that gives a predetermined optical function to the base material is bonded to the optical function surface of the base material made of an optical material;
Bonded to at least one optical functional surface of the base material or the auxiliary material or a surface connected to the optical functional surface,
A correction member that suppresses deformation of the main body due to a difference in material between the base material and the auxiliary material is joined.

The invention according to claim 2 is the bonded optical element according to claim 1,
The correction member imparts an optical function to the main body.
The invention according to claim 3 is the bonded optical element according to claim 1,
The correction member is bonded around the effective optical surface of the main body.

The invention according to claim 4 is the bonding optical element according to claim 1,
The correction member has a rotationally symmetric shape, and a center axis thereof substantially coincides with an optical axis of the main body.

The invention according to claim 5 is the bonded optical element according to claim 1,
The correction member has an annular shape, and the center axis thereof substantially coincides with the optical axis of the main body.

The invention according to claim 6 is the bonded optical element according to claim 5,
The correction member is characterized in that an inner diameter of the annular portion is larger than a diameter of an effective optical surface of the main body portion.

The invention according to claim 7 is the bonded optical element according to claim 1,
The correction member includes a plurality of sub correction members.
The invention according to claim 8 is the bonded optical element according to claim 1,
The correction member is composed of at least two sub correction members made of different materials.

The invention according to claim 9 is the bonded optical element according to claim 1,
The base material and the secondary material are different in at least one of thermal expansion coefficient and humidity expansion coefficient.

The invention according to claim 10 is the bonded optical element according to claim 1,
Each of the base material and the auxiliary material is composed of one member.
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αs1, and the thermal expansion coefficient of the correction member is αs2,
If αs1 is larger than αB, the correction member whose αs2 is larger than αB is
If αs1 is smaller than αB, the correction member having αs2 smaller than αB is
The bonding surface of the base material and the auxiliary material is bonded to an optical function surface of the base material or a surface connected to the optical function surface.

The invention according to claim 11 is the bonded optical element according to claim 1,
The base material and the secondary material are each composed of one member,
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αsl, and the thermal expansion coefficient of the correction member is αs2,
If αs1 is larger than αB, the correction member whose αs2 is smaller than αs1 is
If αs1 is smaller than αB, the correction member in which αs2 is larger than αs1,
It is characterized in that the base material and the secondary material are joined to an optical functional surface of the secondary material different from the joint surface or a surface connected thereto.

The invention according to claim 12 is the bonded optical element according to claim 1,
Each of the base material and the auxiliary material is composed of one member,
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αsl, and the thermal expansion coefficient of the correction member is αs2,
If αsl is larger than αB, the correction member having αs2 larger than αs1 is
If αsl is smaller than αB, the correction member in which αs2 is smaller than αs1,
It joins to the optical function surface of the said submaterial except the junction part of the said base material and the said submaterial, or the surface connected to it.

The invention according to claim 13 is the bonded optical element according to claim 1,
Each of the base material and the auxiliary material is composed of one member,
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αsl, and the thermal expansion coefficient of the correction member is αs2,
If αs1 is larger than αB, the correction member whose αs2 is smaller than αB is
If αs1 is smaller than αB, the correction member having αs2 larger than αB is
It joins to the optical function surface of the said base material except the junction part of the said base material and the said submaterial, or the surface connected to it.

The invention according to claim 14 is the bonded optical element according to claim 1,
The base material and the secondary material are each composed of one member, and the base material and the secondary material are:
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αs1, and the thermal expansion coefficient of the correction member is αs2,
If αs1 is larger than αB, the correcting member is such that αs2 is smaller than αs1 and larger than αB.
If αsl is smaller than αB, αs2 is larger than αs1 and is joined via the correction member smaller than αB.

The invention according to claim 15 is the bonded optical element according to claim 1,
The base material and the subsidiary material are glasses having different material properties.
The invention according to claim 16 is the bonded optical element according to claim 1,
The base material is glass, and the secondary material is an energy curable resin.

The invention according to claim 17 is the bonded optical element according to claim 1,
The correction member is the same as the material of the base material or the auxiliary material.
The invention according to claim 18 is the bonded optical element according to claim 1,
A plurality of the auxiliary materials are provided, and are joined to at least one optical function surface of the base material, the other auxiliary material, or the correction member or a surface connected thereto.

  An optical device according to a nineteenth aspect includes at least one cemented optical element according to any one of the first to eighteenth aspects.

  According to the present invention, it is possible to efficiently suppress surface shape changes such as the radius of curvature of the optical function surface of the cemented optical element due to environmental changes.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a cross-sectional view of a compound lens as an embodiment of a cemented optical element. Here, the compound lens generally refers to a lens formed by forming a resin layer or the like on at least one optical functional surface of a glass lens.

  However, the configuration of the compound lens to which the present invention can be applied is not limited to “glass lens + resin layer”, but “resin lens (plastic lens) + resin layer”, “glass lens + glass layer”, “resin lens + It can also be applied to a “glass layer”.

  FIG. 1 shows a cross-sectional view of a normal compound lens. This compound lens has a structure in which an energy curable resin sub-material 2a is tightly bonded to the second optical surface s2 of the glass substrate 1a constituting the concave lens. And the surface shape (curvature radius, aspherical coefficient, etc.) of the first optical surface s1, the second optical surface s2, and the third optical surface s3, the optical axis direction spacing of these optical functional surfaces, and the glass substrate 1a. By arbitrarily selecting the material of the resin secondary material 2a (mainly paying attention to the refractive index and the hot number), a predetermined optical function can be exhibited. This compound lens has an axisymmetric shape with the optical axis 3 as the central axis.

In this composite lens, the materials of the glass substrate 1a and the resin sub-material 2a are different. As a whole, material property values such as a thermal expansion coefficient and a humidity expansion coefficient have spatial asymmetry with respect to the optical axis direction. For this reason, it is anticipated that the cross-sectional shape of the compound lens will be warped and deformed upward or downward depending on environmental changes such as temperature changes and humidity changes.
(First embodiment)
FIG. 2 shows a cross-sectional view of the compound lens according to the first embodiment of the present invention. This compound lens has a structure in which an energy curable correction member 2b is newly tightly bonded to the first optical surface s1 of the glass substrate 1a of the normal compound lens in FIG. Yes. This compound lens also has an axisymmetric shape with the optical axis 3 as the central axis. Further, the “continuous surface s7” refers to the outer peripheral surface of the first optical surface s1, the second optical surface s2, and the third optical surface s3 as the effective optical surface of the compound lens body. This can generally be said to be a position where correction for environmental deformation is possible, the significance of which will be described later.

  In FIG. 2, the newly provided correction member 2 b has a role of correcting warpage deformation of the compound lens main body according to environmental changes such as temperature change and humidity change. By using such a correction member 2b, the compound lens of the present embodiment can suppress the upward or downward convex warping deformation of the entire compound lens, as compared with a normal compound lens.

  Further, the correction member 2b may have a function of adding optical added value such as a diaphragm function in addition to the function of correcting deformation. In such a case, the correction member 2b is referred to as an “additional member”. You can also. However, in the description of the present embodiment, the case where the correction member 2b is used mainly as a deformation correction member will be described as an example.

Hereinafter, the function of suppressing the environmental deformation of the compound lens of the present embodiment will be described in comparison with the environmental deformation of a normal compound lens.
First, preconditions for considering the environmental deformation of the compound lens are determined. First, the geometric shape of the compound lens is an optical design shape, which is achieved at some reference temperature (usually room temperature). Hereinafter, such a temperature as a base of optical design is referred to as a design reference temperature.

  Secondly, only the temperature change from the design reference temperature is taken as the environmental change, and only the thermal expansion coefficient is considered as the material property value related to the environmental deformation. Further, it is assumed that the temperature distribution of the compound lens is uniform.

  Consider a state in which an environmental deformation (temperature deformation, thermal deformation) due to a temperature change has occurred in the compound lens under the preconditions described above. FIG. 3 and FIG. 4 are schematic views of environmental deformation when each compound lens is cooled and the temperature is lowered.

  As shown in FIG. 3, in a normal compound lens, when cooled and the temperature is lowered, an upward convex warping deformation occurs as indicated by an arrow 4a. This is because the resin generally has a larger coefficient of thermal expansion than glass, and when the same temperature change amount is given, the resin sub-material 2a has a larger amount of thermal strain than the glass substrate 1a. On the contrary, when the temperature rises due to heating, downward convex warping deformation in the direction opposite to the arrow 4a occurs.

  In a normal compound lens, the surface shape expressed by the radius of curvature of the optical function surfaces s1, s2, s3, etc., as the temperature decreases or increases, that is, as the temperature departs from the design reference temperature. Deviates from the design value. Therefore, an optical system using such a composite lens is often more sensitive to temperature changes in optical performance than an optical system that does not use a composite lens. Therefore, in order to satisfy the predetermined optical performance, the usable temperature range must be narrowed.

  Next, as shown in FIG. 4, in the compound lens of the present embodiment, warping deformation in the direction indicated by the arrow 4a is induced by the difference in thermal expansion coefficient between the resin secondary material 2a and the glass substrate 1a as the temperature decreases. Is done. However, the warp deformation in the direction indicated by the arrow 4b is induced by the difference in thermal expansion coefficient between the newly provided correction member 2b and the glass substrate 1a. Therefore, the warp deformations of both are canceled out, and the amount of warp deformation generated in the compound lens as a whole becomes small. Even when the temperature of the compound lens is increased due to heating, the warp deformation amount of the entire compound lens becomes small for the same reason.

  That is, in the compound lens of the present embodiment, the newly provided correction member 2b has the effect of reducing the environmental deformation of the cemented optical element composed of the glass substrate 1a and the resin sub-material 2a, that is, the role as a deformation correction member. You can see that

  In addition, the warp deformation suppressing effect in the present embodiment has a feature that it is autonomously expressed by a necessary amount according to a temperature change. In other words, it is optimal depending on the structural characteristics of the bonding optical element itself, regardless of how far the temperature is from the design reference temperature, and without using a special device for detecting such temperature information by any means. A warp deformation suppressing effect is obtained.

  That is, in the present embodiment, since the warp deformation due to temperature change can be effectively suppressed as a whole compound lens as compared with a normal compound lens, the usable temperature range that guarantees a predetermined optical performance can be expanded. it can. In other words, it can be said that the optical performance of the optical device using the compound lens of the present embodiment is more robust to temperature changes than the optical device using a normal compound lens.

  In the present embodiment, in order to suppress the warpage deformation that is a non-similar deformation due to a temperature change, as shown in FIG. 4, the warpage deformation due to only the glass substrate 1 a and the resin sub-material 2 a is offset. However, it is desirable that the correction member 2b be tightly bonded to an effective place.

  For this reason, in this embodiment, the correction member newly provided in consideration of the relative relationship regarding the thermal expansion coefficient between each component (glass substrate 1a and resin secondary material 2a) of the compound lens and the correction member 2b newly provided. The surface to which 2b is brought into close contact is defined as the first optical surface s1 of the glass substrate 1a or the surface s7 connected thereto.

  In addition, when the material of the newly provided correction member 2b is not energy curable resin and its thermal expansion coefficient is smaller than that of the resin secondary material 2a, the newly provided correction member 2b is made of glass substrate 1a and energy curable resin. It is good to form in the 3rd optical surface s3 which is not the joint surface s2 of the resin submaterial 2a, or the surface connected to it.

  However, in the case of using a normal compound lens composed of the glass base material 1a and the resin sub-material 2a, considering the difficulty of production, cost, etc., as the material of the correction member 2b newly provided for suppressing temperature deformation, It is desirable to select an energy curable resin.

  As described above, when the correction member 2b is newly formed on the optical surface of the normal compound lens or a surface connected thereto, the asymmetry of the thermal expansion coefficient in the optical axis direction in the compound lens, which is the main cause of the warp deformation due to the temperature change. It is based on the design philosophy of balancing the nature (increasing symmetry).

  That is, in the case of a compound lens composed of two layers of the glass substrate 1a and the resin sub-material 2a, the correction member 2b is newly provided as the third layer, and a sandwich structure is formed. Symmetry can be increased.

  In the present embodiment, the shape of the newly provided correction member 2b is annular, and the center axis (not shown) substantially coincides with the optical axis 3 of the optical system including the glass substrate 1a and the resin sub-material 2a. Yes. In this case, the inner diameter D2 of the hole of the correction member 2b is desirably larger than the optical effective diameter Dl of the first optical surface s1 of the glass substrate 1a.

  Note that the shape of the newly provided correction member 2b may be a general rotationally symmetric shape. That is, the above-described annular body is a case where a hole is formed on the center side of the optical system, but may be a rotationally symmetric shape without a hole. For example, if the correction member 2b is thin in the optical axis direction in the optical effective surface of the composite optical element and the optical functional surface shape is substantially equal to the optical functional surface shape of the bonded surface, the optical performance can be improved even without a hole. This is because it has almost no effect.

  The geometric characteristics of the correction member 2b of the present embodiment can achieve an effect of suppressing environmental deformation due to a temperature change without affecting the optical design (optical function) at the design reference temperature with respect to a normal compound lens. It is said.

  In other words, in the present embodiment, as described above, it is not necessarily realized only as a new design technology for a composite lens and an optical system, but an improvement technology (added-value technology) for a normal composite lens and an optical component using the same. Granted).

In addition, as for the correction member 2b of this embodiment, it is desirable to make it the same as the resin submaterial 2a originally formed in the 2nd optical surface s2 of the glass base material 1a.
This is because by unifying the material of the resin sub-material 2a and the correction member 2b, it is expected to comprehensively suppress warpage deformation of the compound lens due to various environmental changes as well as temperature changes. In other words, if the material of the resin secondary material 2a and the correction member 2b are the same, the volume change behavior of the resin secondary material 2a and the correction member 2b will be the same for any environmental change, and the composite defined as a measure against temperature deformation. It is considered that the structural design of the lens functions as a countermeasure against warp deformation caused by any environmental change such as humidity change.

Furthermore, by unifying the materials of the resin secondary material 2a and the correction member 2b, it is possible to prevent the complex lens molding machine from becoming complicated, and to expect secondary effects such as reduction in the procurement cost of the resin material. .
Note that the geometric and material features of the correction member 2b in this embodiment are only one form for carrying out the present invention. For example, the newly provided correction member 2b may be divided into a plurality of pieces and joined to at least one optical function surface of the glass base material 1a and the resin sub-material 2a or a surface connected thereto. The plurality of regions may be made of different materials.

  In addition, as a requirement for the compound lens of the present embodiment, the shape of the newly provided correction member 2b is used when aiming at the effect of suppressing warpage deformation due to a temperature change even if the change in optical function is allowed with respect to a normal compound lens. Is not necessarily a ring. Further, the central axis does not necessarily need to approximately coincide with the optical axis 3 of the compound lens composed of the glass substrate 1a and the resin sub-material 2a. Furthermore, the inner diameter D2 of the hole does not necessarily need to be larger than the effective optical diameter Dl of the first optical surface s1 of the glass substrate 1a.

  In the present embodiment, the size of the correction member 2b newly provided varies depending on what is selected as the material of the correction member 2b. This basically depends on the difference in coefficient of thermal expansion between the correction member 2b and the counterpart (glass substrate 1a or resin sub-material 2a) that is the adherend. Generally, the larger the difference, the smaller the size of the newly provided correction member 2b.

  Here, the relationship between the thermal expansion coefficients of the glass substrate 1a, the resin secondary material 2a, and the correction member 2b and the relationship between the bonding positions of the correction member 2b are listed. The glass base material 1a and the resin secondary material 2a are each composed of a single member, the thermal expansion coefficient of the glass base material 1a is αB, the thermal expansion coefficient of the resin secondary material 2a is αs1, and the thermal expansion of the correction member 2b. The coefficient is αs2.

  In the above, as a first example, for example, if αs1 is larger than αB, the correction member 2b is larger than αB, and if αs1 is smaller than αB, the correction member 2b is smaller than αB. It joins to the optical function surface of the glass base material 1a different from the joining surface of 1a and the resin submaterial 2a, or the surface connected to it. The configuration in this case is shown in FIG.

  As a second example, for example, if αs1 is larger than αB, the correction member 2b is smaller than αs1, and if αs1 is smaller than αB, the correction member 2b is larger than αs1 and the glass substrate 1a and the resin. It joins to the optical function surface of the resin secondary material 2a different from the joint surface of the secondary material 2a or the surface connected to it. The configuration in this case is shown in FIG.

  As a third example, for example, if αsl is greater than αB, the correction member 2b having αs2 larger than αs1 is used. If αsl is smaller than αB, the correction member 2b having αs2 smaller than αs1 is formed using the glass substrate 1a and the resin. It joins to the optical function surface of the resin secondary material 2a including the joining surface of the secondary material 2a as a small region or a surface connected to it. The configuration in this case is shown in FIG.

  As a fourth example, for example, if αs1 is larger than αB, the correction member 2b is smaller than αB. If αs1 is smaller than αB, the correction member 2b is larger than αB. It joins to the optical function surface of the glass base material 1a which contains the joining surface of the submaterial 2a as a small area, or the surface connected to it. The configuration in this case is shown in FIG.

  As a fifth example, for example, if αs1 is larger than αB, the correction member 2b is smaller than αs1 and larger than αB, and if αsl is smaller than αB, αs2 is larger than αs1 and smaller than αB. The glass substrate 1a and the resin secondary material 2a are joined via the member 2b. The configuration in this case is shown in FIG.

As for the geometric shape including the size of the newly provided correction member 2b, it is desirable to find the best one while confirming the effect by the structural analysis by the finite element method.
Further, in this embodiment, only the temperature deformation is mainly focused on as the environmental deformation. However, if the temperature is replaced with the humidity and the thermal expansion coefficient is replaced with the humidity expansion coefficient, the structure of the compound lens is basically the same as the warp deformation due to the humidity change. It also functions as a suppression structure.

  In addition, the compound lens of the present embodiment is configured by closely bonding the three parts of the glass substrate 1a, the resin secondary material 2a, and the correction member 2b, but it goes without saying that the number of these components is not limited. Yes. In other words, the compound lens to which the present invention can be applied may be one in which a plurality of glass substrates and energy curable resin sub-materials are closely bonded.

Here, the result of the structural analysis by the finite element method relating to the environmental deformation of the compound lens of the present embodiment is shown in comparison with the case of a normal compound lens.
FIG. 10 shows a simulation model of a normal compound lens in which a resin sub-material 2a is closely bonded to a glass substrate 1a.

  FIG. 11 shows a simulation model of the compound lens of the present embodiment in which the resin sub-material 2a and the correction member 2b are tightly bonded to the glass substrate 1a. The simulation model is an axisymmetric model, and the cross-sectional shape of the compound lens shows only the right half from the center of the optical axis.

FIG. 12 is a displacement distribution diagram in the optical axis direction (the direction of the optical axis 3) when a normal compound lens having a design reference temperature of 20 ° C. is cooled to −60 ° C.
FIG. 13 is an optical axis direction displacement distribution diagram when the compound lens of the present embodiment having a design reference temperature of 20 ° C. is cooled to −60 ° C.

FIG. 14 is an optical axis direction displacement distribution diagram when a normal compound lens having a design reference temperature of 20 ° C. is heated to 100 ° C.
FIG. 15 is an optical axis direction displacement distribution diagram when the compound lens of the present embodiment having a design reference temperature of 20 ° C. is heated to 100 ° C.

  In the displacement distribution diagrams in FIGS. 12, 13, 14, and 15, the range of displacement in the optical axis direction represented by contour lines is unified. Further, these displacement distribution diagrams also serve as deformation diagrams, and the deformation magnification is 60 times.

  As shown in FIGS. 12 and 14, in the normal compound lens, oblique contour lines are generated in the glass substrate 1 a, and clear warp deformation is recognized as the entire compound lens. On the other hand, as shown in FIGS. 13 and 15, in the compound lens of the present embodiment, such oblique contour lines with respect to the glass substrate 1a are not seen, and warpage deformation is suppressed as a whole compound lens. I understand.

  That is, in the compound lens of the present embodiment, the amount of deviation from the design value of each optical function surface shape accompanying a change in temperature is smaller than that of a normal compound lens. The results of graphing this for the first optical surface s1 of the glass substrate 1a are shown in FIGS.

FIG. 16 shows the displacement in the optical axis direction of a normal compound lens, and FIG. 17 shows the displacement in the optical axis direction of the compound lens of this embodiment.
When comparing FIG. 16 and FIG. 17, the compound lens of this embodiment has a shape change amount of the first optical surface s1 of the glass substrate la due to a temperature change from −60 ° C. to 100 ° C. as compared with a normal compound lens. It can be seen that (deviation 5 from the design value in the optical direction) can be suppressed to half or less. That is, it can be said that the compound lens of the present embodiment has an optical performance that is more robust with respect to changes in temperature environment than a normal compound lens.
(Second Embodiment)
In this embodiment, a cemented lens as shown in FIG. 18 is considered. Here, the cemented lens generally refers to a lens formed by bonding and bonding two or more glass lenses made of different materials via an adhesive or the like. However, the configuration of the cemented lens to which the present invention can be applied is not limited to “glass lens + glass lens”, but can also be applied to “glass lens + resin lens” and “resin lens + resin lens”.

  FIG. 18 shows a cross-sectional view of a normal cemented lens. This compound lens has a structure in which a glass secondary material 12a constituting a concave lens is adhesively bonded to a second optical surface s12 of a glass substrate 11a constituting a convex lens. Then, the surface shape of the first optical surface s11, the second optical surface s12, and the third optical surface s13, the distance between the optical function surfaces in the optical axis direction, and the materials of the glass base material 11a and the glass auxiliary material 12a are arbitrarily designed. Thus, a predetermined optical function is expressed. This normal cemented lens has an axisymmetric shape with the optical axis 13 as the central axis.

  Moreover, in FIG. 18, the glass base material 11a and the glass subsidiary material 12a are made of different glass materials. That is, as a whole of this cemented lens, generally, material property values such as a thermal expansion coefficient and a humidity expansion coefficient have a spatial asymmetry with respect to the optical axis direction. Thereby, it is expected that the cross-sectional shape of the cemented lens is warped and deformed upward or downward depending on environmental changes such as temperature change and humidity change.

  FIG. 19 shows a cross-sectional view of the cemented lens of the present embodiment. This cemented lens has a configuration in which a correction member 12b is newly bonded and joined to a first optical surface s11 of a glass substrate 11a of a normal cemented lens and a surface s17 continuous therewith. Note that the cemented lens of the present embodiment also has an axisymmetric shape with the optical axis 13 as the central axis.

  In the cemented lens of the present embodiment, the newly provided correction member 12b has a role of correcting warpage deformation as the cemented lens main body according to environmental changes such as temperature change and humidity change. With the introduction of the correction member 12b, the cemented lens of the present embodiment suppresses the upward or downward convex warping deformation of the cemented lens as a whole, as compared with a normal cemented lens.

  In addition, since the function of suppressing the environmental deformation of the cemented lens of the present embodiment is the same as that of the above-described compound lens of the first embodiment, detailed description thereof is omitted. 20 and 21 are schematic diagrams.

  In the cemented lens of the present embodiment, the newly provided correction member 12b is made of the same material as the glass secondary material 12a that is originally bonded and bonded to the glass substrate 11a. It ’s not limited. That is, rubber, plastic, metal, or the like can be used as the material of the correction member 12b newly provided.

  The newly provided correction member 12b needs to be adhesively bonded to a place where there is an effect of suppressing warpage deformation due to temperature deformation of the original cemented lens. For example, the new correction member 12b is bonded and bonded to a place where the symmetry in the optical axis direction of the thermal expansion coefficient of the entire cemented lens including the correction member 12b is further increased.

Next, the result of the structural analysis by the finite element method regarding the environmental deformation of the cemented lens of the present embodiment is shown in comparison with the case of a normal cemented lens.
FIG. 22 shows a simulation model of a normal cemented lens in which a glass secondary material 12a is bonded and bonded to a glass substrate 11a.

FIG. 23 shows a simulation model of the cemented lens of the present embodiment in which the glass secondary material 12a and the correction member 12b are bonded and bonded to the glass substrate 11a.
FIG. 24 is a displacement distribution diagram in the optical axis direction (direction of the optical axis 13) when a normal compound lens having a design reference temperature of 20 ° C. is cooled to −60 ° C.

FIG. 25 is an optical axis direction displacement distribution diagram when the compound lens of the present embodiment having a design reference temperature of 20 ° C. is cooled to −60 ° C.
FIG. 26 is a displacement distribution diagram in the optical axis direction when a normal compound lens having a design reference temperature of 20 ° C. is heated to 100 ° C.

FIG. 27 is a displacement distribution diagram in the optical axis direction when the compound lens of the present embodiment having a design reference temperature of 20 ° C. is heated to 100 ° C.
The displacement distribution diagrams in FIGS. 24 to 27 also serve as deformation diagrams, and the deformation magnification is 100 times.

28 and 29 show how the first optical surface s11 of the glass substrate 11a is deformed.
As is apparent from FIGS. 24 to 29, the cemented lens of the present embodiment has the first optical surface s11 of the glass substrate 11a due to a temperature change over −60 ° C. to 100 ° C. as compared with a normal cemented lens. It can be seen that the amount of change in shape (deviation 15 from the design value in the optical direction) can be significantly suppressed. That is, it can be said that the cemented lens of the present embodiment has an optical performance that is more robust with respect to changes in temperature environment than an ordinary cemented lens.

It is sectional drawing of a normal compound lens. It is sectional drawing of the compound lens of 1st Embodiment. It is a schematic diagram showing a deformation | transformation at the time of cooling a normal compound lens. It is a schematic diagram showing a deformation | transformation at the time of cooling the compound lens of 1st Embodiment. It is a schematic diagram which shows the structure of the compound lens of 1st Embodiment. It is a schematic diagram which shows the structure of the compound lens of 1st Embodiment. It is a schematic diagram which shows the structure of the compound lens of 1st Embodiment. It is a schematic diagram which shows the structure of the compound lens of 1st Embodiment. It is a schematic diagram which shows the structure of the compound lens of 1st Embodiment. It is a figure which shows the simulation model of a normal compound lens. It is a figure which shows the simulation model of the compound lens of 1st Embodiment. It is a figure which shows the simulation model at the time of cooling a normal compound lens. It is a figure which shows the optical axis direction displacement distribution at the time of cooling the compound lens of 1st Embodiment. It is a figure which shows the optical axis direction displacement distribution at the time of heating a normal compound lens. It is a figure which shows the optical axis direction displacement distribution at the time of heating the compound lens of 1st Embodiment. It is a figure which shows the deformation | transformation of the optical function surface at the time of heating and cooling a normal compound lens. It is a figure which shows the deformation | transformation of the optical function surface at the time of heating and cooling the compound lens of 1st Embodiment. It is sectional drawing of a normal cemented lens. It is sectional drawing of the cemented lens of 2nd Embodiment. It is a schematic diagram showing a deformation | transformation at the time of cooling a normal cemented lens. It is a schematic diagram showing a deformation | transformation at the time of cooling the cemented lens of 2nd Embodiment. It is a figure which shows the simulation model of a normal cemented lens. It is a figure which shows the simulation model of the cemented lens of 2nd Embodiment. It is a figure which shows the optical axis direction displacement distribution at the time of cooling a normal cemented lens. It is a figure which shows the optical axis direction displacement distribution at the time of cooling the cemented lens of 2nd Embodiment. It is a figure which shows the optical axis direction displacement distribution at the time of heating a normal cemented lens. It is a figure which shows the optical axis direction displacement distribution at the time of heating the cemented lens of 2nd Embodiment. It is a figure which shows the deformation | transformation of the optical function surface at the time of heating and cooling a normal cemented lens. It is a figure which shows the deformation | transformation of the optical function surface at the time of heating and cooling the cemented lens of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Glass base material 2a Resin secondary material 2b Correction member 3 Optical axis 4a 4b Expressing upward convex warpage deformation 5 Depressing downward convex warpage deformation 5 Amount of optical function surface shape change due to temperature change 12a Glass secondary material 12b Correction member 13 Light Axis 14a 14b representing upward convex warpage deformation 15 representing downward convex warpage deformation Amount of change in shape of optical functional surface s1 due to temperature change s1 First optical surface s2 Second optical surface s3 Third optical surface s7 Similar surface 11a Glass substrate s11 First optical surface s12 Second optical surface s13 Third optical surface s17 Similar surface D1 Effective optical diameter D2 Inner diameter D11 of correction member 2b Optical effective diameter D12 Inner diameter of correction member 12b

Claims (19)

A main body part in which a secondary material made of an optical material that gives a predetermined optical function to the base material is bonded to the optical function surface of the base material made of an optical material;
Bonded to at least one optical functional surface of the base material or the auxiliary material or a surface connected to the optical functional surface,
It is formed by bonding a correction member that suppresses deformation of the main body due to a difference in material between the base material and the auxiliary material.
A bonded optical element. The correction member provides an optical function to the main body.
The bonded optical element according to claim 1. The correction member is bonded around the effective optical surface of the main body,
The bonded optical element according to claim 1. The correction member has a rotationally symmetric shape, and the center axis thereof substantially coincides with the optical axis of the main body part.
The bonded optical element according to claim 1. The correction member has an annular shape, and the central axis of the correction member substantially coincides with the optical axis of the main body.
The bonded optical element according to claim 1. The correction member has an annular inner diameter larger than the diameter of the effective optical surface of the main body,
The bonded optical element according to claim 5. The correction member is composed of a plurality of sub correction members.
The bonded optical element according to claim 1. The correction member includes at least two sub correction members made of different materials.
The bonded optical element according to claim 1. The base material and the secondary material are different in at least one of their thermal expansion coefficient or humidity expansion coefficient,
The bonded optical element according to claim 1. Each of the base material and the auxiliary material is composed of one member.
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αs1, and the thermal expansion coefficient of the correction member is αs2,
If αs1 is larger than αB, the correction member whose αs2 is larger than αB is
If αs1 is smaller than αB, the correction member having αs2 smaller than αB is
Bonding to the optical functional surface of the substrate different from the bonding surface of the substrate and the secondary material or a surface connected to it,
The bonded optical element according to claim 1. The base material and the secondary material are each composed of one member,
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αsl, and the thermal expansion coefficient of the correction member is αs2,
If αs1 is larger than αB, the correction member whose αs2 is smaller than αs1 is
If αs1 is smaller than αB, the correction member in which αs2 is larger than αs1,
Bonding to the optical function surface of the secondary material different from the bonding surface of the base material and the secondary material or a surface continuous therewith,
The bonded optical element according to claim 1. Each of the base material and the auxiliary material is composed of one member,
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αsl, and the thermal expansion coefficient of the correction member is αs2,
If αsl is larger than αB, the correction member having αs2 larger than αs1 is
If αsl is smaller than αB, the correction member in which αs2 is smaller than αs1,
Bonding to the optical function surface of the secondary material excluding the joint portion of the base material and the secondary material or a surface connected to it.
The bonded optical element according to claim 1. Each of the base material and the auxiliary material is composed of one member,
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αsl, and the thermal expansion coefficient of the correction member is αs2,
If αs1 is larger than αB, the correction member whose αs2 is smaller than αB is
If αs1 is smaller than αB, the correction member having αs2 larger than αB is
Bonding to the optical functional surface of the base material or a surface connected to the base material excluding the joint portion of the base material and the auxiliary material,
The bonded optical element according to claim 1. The base material and the secondary material are each composed of one member, and the base material and the secondary material are:
When the thermal expansion coefficient of the base material is αB, the thermal expansion coefficient of the secondary material is αs1, and the thermal expansion coefficient of the correction member is αs2,
If αs1 is larger than αB, the correcting member is such that αs2 is smaller than αs1 and larger than αB.
If αsl is smaller than αB, αs2 is larger than αs1 and smaller than αB.
Joined through,
The bonded optical element according to claim 1. The base material and the secondary material are glasses having different material properties from each other.
The bonded optical element according to claim 1. The base material is glass, and the secondary material is an energy curable resin.
The bonded optical element according to claim 1. The correction member is the same as the material of the base material or the auxiliary material,
The bonded optical element according to claim 1. A plurality of the auxiliary materials are provided and bonded to at least one optical functional surface of the base material or another auxiliary material or the correction member or a surface connected thereto.
The bonded optical element according to claim 1. It comprises at least one bonding optical element according to any one of claims 1 to 18.
An optical device.