JP3890101B2 - Imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus including an optical member integrally formed with a plurality of refracting surfaces and a plurality of reflecting surfaces, which is used for a silver salt camera, a video camera, an electronic still camera, and the like.
[0002]
[Related technologies]
Using a transparent optical member in which a plurality of refractive surfaces and a plurality of reflecting surfaces are integrally formed, a light beam enters the inside of the transparent optical member from one refracting surface, and is repeatedly reflected on the plurality of reflecting surfaces for another refraction. Japanese Patent Application No. 7-65109 and Japanese Patent Application No. 7-123256 disclose a zoom optical system having a plurality of transparent optical members configured to emit light from the surface to the outside. An image pickup apparatus having a structure for forming an image on a solid-state image pickup device using such an optical system is disclosed in Japanese Patent Application No. 7-65104, Japanese Patent Application No. 7-65106, Japanese Patent Application No. 7-65107, and Japanese Patent Application No. 7-65108. No. 7-65111.
[0003]
[Problems to be solved by the invention]
However, no mention is made of the structure of the optical device corresponding to the temperature change.
[0004]
The present invention has been made under such circumstances, and is configured such that a light beam enters the inside from one refracting surface, is repeatedly reflected by a plurality of reflecting surfaces, and exits from the other refracting surface to the outside. A zoom optical system having first, second, and third optical members that are sequentially arranged with bent outer shapes, a first moving base that moves while holding the second optical member, and the third An image pickup apparatus having a second moving base that holds and moves the optical member and prevents image deterioration due to expansion and contraction of the optical member due to a temperature change and a change in refractive power due to the expansion and contraction. It is what.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, the imaging apparatus is configured as described in (1) and (2) below.
(1) A first, second, and sequentially arrayed with a bent outer shape configured such that a light beam is incident on the inside from an incident light surface, and is repeatedly reflected by a plurality of reflecting surfaces and emitted from the exit light surface to the outside. A zoom optical system having a third optical member, an image sensor that captures a subject image formed by the zoom optical system, a first movement base that moves while holding the second optical member, A second moving base that moves while holding the third optical member, a guide rail that regulates the moving direction of the first and second moving bases, the first optical member, the guide rail, and the imaging An imaging device comprising a base supporting the element,
The exit light surface of the first optical member and the incident light surface of the second optical member are disposed to face each other, and the exit light surface of the second optical member and the incident light surface of the third optical member are disposed to face each other. And the light emitting surface of the third optical member and the imaging element are arranged to face each other,
Matching the emission optical axis of the second optical member and the incident optical axis of the third optical member;
The end of the incident light surface vicinity of the first optical member is supported more on the base in the vicinity of the guide rail,
In the vicinity of the emission optical axis of the second optical member and the incident optical axis of the third optical member, the guide rail is arranged in parallel with these optical axes and supported by the base ,
More held on the first moving base in the guide rail near the ends of the exit light surface vicinity of the second optical member,
It said third end portion of the incident light plane near the optical member is more retained in the second moving base near the guide rail, the imaging apparatus.
(2) The first, second, and sequentially arranged light beams that are configured to be incident on the inside from the incident light surface and repeatedly reflected on the plurality of reflecting surfaces to be emitted to the outside from the exit light surface. A zoom optical system having a third optical member, an image sensor that captures a subject image formed by the zoom optical system, a first movement base that moves while holding the second optical member, A second moving base that moves while holding the third optical member, a guide rail that regulates the moving direction of the first and second moving bases, the first optical member, the guide rail, and the imaging An imaging device comprising a base supporting the element,
The exit light surface of the first optical member and the incident light surface of the second optical member are disposed to face each other, and the exit light surface of the second optical member and the incident light surface of the third optical member are disposed to face each other. And the light emitting surface of the third optical member and the imaging element are arranged to face each other,
Matching the emission optical axis of the second optical member and the incident optical axis of the third optical member;
The end of the incident light surface vicinity of the first optical member is supported more on the base in the vicinity of the guide rail,
In the vicinity of the emission optical axis of the second optical member and the incident optical axis of the third optical member, the guide rail is arranged in parallel with these optical axes and supported by the base,
The end of the incident light surface vicinity of the first optical member is supported more base in the vicinity of the guide rail,
The end of the exit light surface vicinity of the second optical member, at the exit light side of the viewed from the guide rail third optical member, and more held in the first moving base,
The end of the incident light surface vicinity of said third optical member, at the exit light side of the viewed from the guide rail first optical member, and more held in the second moving base,
Imaging in which the holding position of the second optical member on the first moving base and the holding position of the third optical member on the second moving base are positions symmetrical with respect to the guide rail. apparatus.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to examples of “imaging devices”. The present invention is not limited to an apparatus having a solid-state imaging device (for example, a CCD) as in the embodiment, and can be similarly implemented in a silver salt camera.
[0015]
【Example】
Example 1
FIG. 1 is a perspective view of an “imaging device” that is Embodiment 1, and this device uses first, second, and third optical members. 2 is a diagram (plan view) viewed from the direction A in FIG. 1, and FIG. 3 is a diagram (side view) viewed from the direction B in FIG. FIG. 4 is an explanatory diagram of each member, and shows a state in which the first, second, and third optical members are removed from FIG. FIG. 5 is an explanatory diagram of the reference optical axes of incident light and reflected light. FIG. 6 is an optical path diagram of incident light and reflected light.
[0016]
In each figure, reference numeral 1 denotes an integrally formed two refracting surfaces (incident light surface 1a and outgoing light surface 1f in FIG. 5) and four reflecting surfaces (1b, 1c, 1d, and 1e in FIG. 5). A first optical member made of plastic, glass, or the like (corresponding to the function of a front group unit in a normal lens), and its one end 1h is a mounting portion 16 of a base (also referred to as a base) 9 (see FIG. 4). ) With mounting screws 17 and 17. Note that the reason why the one end 1h is attached is based on the idea of absorbing expansion and contraction due to temperature change, particularly when the material is plastic. As will be described later, one end of each of the second optical member 2 and the third optical member 3 is fixed in the same way, and can expand and contract in the longitudinal direction (substantially in the C and D directions). In addition, fastening one end with a screw is also effective in the sense that the stress caused by screwing does not adversely affect the portion where the optical performance is required (the optical path from 1a to 1b). Further, in this embodiment, when the material is plastic, a gate (injection port at the time of injection molding) is provided on the end face 1i side of the one end 1h. This is also a consideration to prevent the gate from affecting the part that requires optical performance.
[0017]
2 is a plastic in which two refracting surfaces (incident light surface 2a and outgoing light surface 2g in FIG. 5) and five reflecting surfaces (2b, 2c, 2d, 2e, 2f in FIG. 5) are integrally formed. Or a second optical member made of glass or the like (variator in a conventional lens), 3 has two refracting surfaces (incident light surface 3a and outgoing light 3g in FIG. 5) and five reflecting surfaces (3b in FIG. 5). , 3c, 3d, 3e, 3f), a third optical member (compensator in a normal lens) made of plastic, glass or the like, which is integrally formed, 4 is a diaphragm means (details of the mechanism are omitted), 5 Is a first moving base having fitting holes 5a and 5a at one end and a U-groove 5b at the other end. The 5a and 5a are connected to the first guide rail stoppers 11 and 11 of the base 9. Installed with screws 13 and 13 The first guide rail 15 and the second guide rail 14 fitted to the second guide rail stoppers 10 and 10 of the base 9 with screws 13 and 13 are fitted together with the first guide rail 15 so that there is no backlash. Are fitted with a degree of freedom in the C and D directions. As a result, the first moving base 5 moves smoothly along the guide rail 15 and in the direction opposite to B and B in FIG. It can be done. Further, the first moving base 5 has an adhesive portion 5d (adhesive portion 5d) for adhering and fixing the second optical member 2 almost directly above the fitting holes 5a, 5a (the front side in FIG. 2 and the E direction in FIG. 3). FIG. 4) is provided, and one end (emitted light side) of the second optical member 2 can be adhered and held at this portion. As shown in FIG. 3, the second optical member 2 and the first moving base 5 are in close contact with each other at the bonding portion 5d, but the other surface 5e (FIG. 4) is lowered by one step from 5d. As shown in FIG. 3, a gap m is formed between the optical member 2 and the surface 5e. The reason for this is to allow the optical member 2 to freely expand and contract in the C and D directions with reference to the bonding portion 5d when an environmental change (temperature change or the like) occurs as described above. Although the gap m is intentionally provided in the drawing, it is also possible to bond and fix only by the 5d portion while not providing m and 5d and 5e on the same surface. 5 is further provided with a rack portion 5c (see FIGS. 2 and 4), which meshes with the screw shaft 7 of the first stepping motor 6. As a result, when the first stepping motor 6 is driven by a circuit (not shown), the first moving base 5 and the second optical member 2 bonded and fixed thereto are sent along the guide rail 15. It will be. The first stepping motor 6 is attached to the first angle 8, and the first angle 8 is fixed to the base 9.
[0018]
In this embodiment, a stepping motor is used as a drive source. However, there is no need to be particular about this, and the first drive base 5 and the second optical member 2 such as a DC motor, an ultrasonic motor, or a voice coil drive are used. Any device that can be driven may be used.
[0019]
Reference numeral 18 denotes a second movement base, and the structure is substantially the same as that of the first movement base 5. Also, fitting holes 18a and 18a are provided at one end, and a U-groove 18b similar to 5b (FIG. 4) is provided at the other end. The 18a and 18a are attached to the first guide rail stoppers 11 and 11 of the base 9. The first guide rail 15 and the third guide rail 22 fitted to the third guide rail stoppers 12 and 12 of the base 9 with screws 13 and 13 are fitted to the first guide rail 15 so as to be free from backlash. The two C and D directions are fitted with a degree of freedom. As a result, like the first moving base 5, the second moving base 18 can move smoothly along the first guide rail 15.
[0020]
The reason why the reference guide rail 15 is made common is that there are the following advantages (1) and (2) compared with the case where the guide rail 15 is separate.
[0021]
(1) The optical member 2 and the optical member 3 perform zoom movement in the direction B and the opposite direction in FIG. At this time, the optical axis emitted from the second optical member 2 and the optical axis incident on the third optical member 3 (optical axes 2f to 3b in FIG. 5 described later) are always in the stop position during and after the movement. Matching is necessary for a high performance zoom mechanism. If the guide rails are separate, the optical axes will not match due to assembly accuracy, component variations, etc., which will adversely affect performance. If the guide rail is common, such a problem is solved.
[0022]
(2) Cost reduction can be achieved by reducing parts and assembly man-hours.
[0023]
The second moving base 18 is provided with an adhesive portion 18d for adhering and fixing the third optical member 3 almost directly above the fitting holes 18a and 18a. At this portion, one end of the third optical member 3 ( (Incident light side) can be adhered and held. Similar to the first moving base 5, a predetermined step is provided between the bonding portion 18 d and the other surface 18 e. This reason is also for coping with environmental changes (temperature changes, etc.). Similarly to the first moving base 5, the second moving base 18 is provided with a rack portion 18 c (see FIGS. 2 and 4) and meshes with the screw shaft 20 of the second stepping motor 19. . As a result, when the second stepping motor 19 is driven by a circuit (not shown), the second moving base 18 and the third optical member 3 bonded and fixed thereto are sent along the guide rail 15. It will be. The second stepping motor 19 is attached to the second angle 21, and the second angle 21 is fixed to the base 9.
[0024]
Reference numeral 23 is an optical low-pass filter, 24 is an IR (infrared) cut filter, and 25 is a CCD (solid-state image sensor), each of which is a well-known means required for converting optical information into an electrical signal. As shown in FIG. 5, the optical information that has passed through the first optical member 1, the second optical member 2, and the third optical member 3 is converted into an electrical signal. In general, the optical low-pass filter 23, the IR cut filter 24, and the CCD 25 are integrally coupled and attached with a predetermined structure, but this structure is not shown here. The CCD 25 is generally connected to a signal processing circuit, but this portion is not shown. 26 is a CCD mounting plate to which the CCD 25 is mounted, 27 is an angle for mounting these on the base 9, and 32 is a protrusion formed by narrowing the angle 27 in the B direction of FIG. (Refer to FIG. 2, in FIG. 1, the dent is seen from the B direction). The CCD mounting plate 26 is coupled to the angle 27 in such a manner that the CCD mounting plate 26 is abutted against the projection 32 by a screw 28 sandwiching the screws 30 and 30 and the spring washer 29. This is because when the light emitted from the exit surface 3g of the third optical member 3 enters the CCD 25, the CCD 25 may not be perpendicular to the surface of the CCD 25 due to component accuracy, assembly errors, and the like. It is for entering at an incident angle. That is, the CCD 25 is tilted with the protrusion 32 as a fulcrum by appropriately tightening or loosening the screws 28, 30, 30.
[0025]
Here, almost directly above the fitting holes 5a, 5a of the first moving base 5 (substantially directly below the optical axis emitted from the second optical member 2. In FIG. 5, each optical axis advances on one plane. The first guide rail 15 exists in the plane perpendicular to the plane, or in the vicinity of the plane, which intersects the plane at the position of the optical axis of 2f to 3b, and the first guide rail 15 has 2f to 3b. The second optical member 2 is adhered and fixed by being substantially parallel to the optical axis), and almost right above the fitting holes 18a, 18a of the second moving base 18 (on the incident optical axis of the third optical member 3). The reason why the third optical member 3 is structured to be bonded and fixed almost directly below will be described below.
[0026]
As described above, the moving bases 5 and 18 holding the second optical member 2 and the third optical member 3 are both fitted to the first guide rail 15 and configured to be movable along this. Yes.
[0027]
When the temperature changes in the environment, the optical member 2 expands or contracts. However, the exit optical axis (the light beam from 2f in FIG. 5) side is almost directly above the fitting holes 5a and 5a. Since it is bonded and fixed to the first moving base 5, it will expand in the direction C or contract in the direction D in FIG. On the other hand, the third optical member 3 is bonded on the side of the incident optical axis (the light beam incident on 3a in FIG. 5) on the side almost 18d above the fitting holes 18a and 18a. 2 expands in the D direction and contracts in the C direction. That is, both have a structure that expands and contracts in opposite directions with respect to the first guide rail 15 as a reference. The optical axis from the second optical member 2 and the incident optical axis of the third optical member 3... From 2f to 3b in FIG. This means a structure that expands and contracts in directions opposite to each other based on the optical axis emitted from the second optical member 2 and the optical axis incident on the third optical member 3. As a result, the light emitted from the second optical member 2 can always enter the same position on the incident light surface 3a (FIG. 5) of the third optical member 3 without being affected by the temperature change.
[0028]
On the other hand, since the first optical member 1 is also fixed to the mounting portion 16 from the base 9 at one end 1h close to the first guide rail 15, the first optical member 1 expands substantially in the C direction on the basis of the one end 1h, and substantially D Will shrink in the direction. This is expansion and contraction in the same direction as the second optical member 2. The first optical member 1 has a dimension in the C direction from the position of the mounting screw 17 to the emission light surface 1f of about 40 mm, and the second optical member 2 is incident from an adhesive fixing portion (position of the emission optical axis from 2f). Since the dimension in the C direction to the optical surface 2a is not so different from about 45 mm, the expansion and contraction amounts of both due to temperature change are about the same. As a result, the light emitted from the light emission surface 1f can be always incident at substantially the same position on the incident light surface 2a of the second optical member 2 without being affected by the temperature change. That is, the optical performance is prevented from deteriorating due to temperature changes.
[0029]
The position of the light emitted from the third optical member 3 (the light beam from 3f) is shifted in the C direction or D direction in FIG. 2 due to the temperature change. This light beam is incident on the CCD 25. The CCD 25 is not particularly required to have the mounting position accuracy in the C direction and D direction with respect to the third optical member 3 (rough accuracy is possible), so no problem occurs.
[0030]
Next, the arrangement of the stepping motors 6 and 19 will be described.
[0031]
In FIG. 2, the first stepping motor 6 is disposed at a position surrounded by the first optical member 1, the second optical member 2, and the third optical member 3. The second stepping motor 19 is disposed at a position surrounded by the second optical member 2, the third optical member 3, and the CCD 25. This is a place where each location is just a dead space in the arrangement of the optical members, and by arranging each stepping motor here, the overall space efficiency is increased and it is possible to contribute to the miniaturization of the apparatus. Further, this position is in the vicinity of the first guide rail 15 which becomes a reference when the first moving base 5 and the second moving base 18 move, and when the respective moving bases are moved, scouring or the like is generated. Also, the position can be minimized, and the optical member can be moved with high accuracy.
[0032]
Further, a first guide rail 15 serving as a reference is disposed in the vicinity of the light emitted from the second optical member 2 and the light incident on the third optical member 3 (same optical axes... 2f to 3b). Therefore, it is possible to minimize the adverse effect of the play during zoom movement on the optical axis from 2f to 3b. Here, a common guide rail can be arranged in the vicinity of the optical axes 1e to 2b in FIG. 5, but the vicinity of 2f to 3b is preferable for the reason (3) below.
[0033]
(3) The first optical member 1 does not move and is always in a fixed position. In contrast, the second optical member 2 and the third optical member 3 always move during zooming. That is, if the guide rail 15 as a reference is arranged in the vicinity of the optical axis of 2f to 3b, which has a large variation factor due to play or the like, the variation factor can be suppressed, and a more accurate zoom mechanism can be obtained. .
[0034]
The operation when the image is taken into the CCD 25 in the above configuration will be described with reference to FIG. Here, the optical path of each light beam in FIG. 5 shows only the principal axis, and the entire behavior of the light flux is disclosed in Japanese Patent Application No. 7-65109 and Japanese Patent Application No. 7-123256, and will not be described in detail here. .
[0035]
In FIG. 5, first, image information of the subject 31 is incident on the incident light surface 1 a of the first optical member 1. Since the first optical member 1 is made of plastic, glass or the like as described above, the image is refracted and incident on the incident light surface 1a by the refractive power. At that time, the control means (not shown) drives the diaphragm mechanism 4 based on the brightness information of the light quantity detection means (not shown) to set the incident light quantity to a predetermined value. The light incident from the incident light surface 1a is repeatedly reflected one after another by the reflecting surfaces 1b, 1c, 1d, and 1e, and is also refracted by the refractive power from the emitting light surface 1f and emitted to the outside. This light ray then enters the incident light surface 2a of the second optical member 2, but is similarly refracted by the refractive power. The reflection surfaces 2b, 2c, 2d, 2e, and 2f of the second optical member 2 are successively reflected one after another and refracted by the refractive power from the exit light surface 2g, and light is emitted to the outside. This light beam then becomes refracted light on the incident light surface 3a of the third optical member 3, enters the inside of the third optical member 3, and is sequentially reflected by 3b, 3c, 3d, 3e, 3f, and refracted light is emitted from 3g. It is injected outside. The light from 3g passes through the low-pass filter 23 and the IR cut filter 24 and is imaged on the CCD 25. Image information from the CCD 25 is signal-processed by a signal processing circuit (not shown) or the like, and finally displayed on a display device (not shown). Looking at this, the operator operates an operating device (not shown) to adjust the subject image to a desired angle of view. In general video cameras and electronic still cameras, this is the act of operating the operation keys on the tele or wide side with a zoom switch. In general, an autofocus operation is performed after the zoom operation, but the control method is well known in the art. Further, during this time, a control unit (not shown) controls the diaphragm means 4 in order to obtain a desired brightness.
[0036]
The following describes how the second optical member 2 and the third optical member 3 are controlled by the above-described zoom key operation by the operator.
[0037]
When the operator operates the key to the tele side, the stepping motors 6 and 19 (FIG. 2) are rotationally driven in a predetermined direction by a control signal from a control unit (not shown). At the same time, the screws 7 and 20 are also rotated. Since the rack portion 5c of the first moving base 5 and the rack portion 18c of the second moving base 18 are engaged with the screws 7 and 20, respectively, the second optical member 2 and the third optical member are engaged. The member 3 is moved by a predetermined amount in the B direction in FIGS. When stopped at an appropriate position, the first moving base 5 or the second moving base 18 is controlled to move slightly in the B direction or in the opposite direction to focus on the CCD 25. 2 and 5 are diagrams showing the state close to the wide end as the device. When the device is further operated to the wide side, the second optical member 2 and the third optical member 3 are opposite to the B direction. However, the amount of movement is less than when moving to the tele side. FIG. 6 shows an optical path diagram of light rays by the optical member of the present embodiment. The state in which the light beam advances while forming an image inside the optical member is shown as a reference. Incidentally, the behavior of the light flux due to the movement of a plurality of optical members having a plurality of refracting surfaces and a plurality of reflecting surfaces during tele / wide operation is described in Japanese Patent Application Nos. 7-65109 and 7-123256. Therefore, it is not specifically described here.
[0038]
It should be noted that the diaphragm means 4 is controlled in a predetermined manner by a predetermined control signal even during these zoom operations. Further, when the apparatus is an electronic still camera, a shutter is necessary. Therefore, it is conceivable that the diaphragm means 4 has a shutter function, a CCD having a shutter function is mounted, or a separate shutter is provided.
[0039]
As described above, according to the present embodiment, a plurality of optical members configured such that a light beam enters the inside from one refracting surface and is repeatedly reflected by a plurality of reflecting surfaces and emitted from another refracting surface to the outside. In the optical apparatus provided with the zoom optical system and the driving means for driving the zoom of the zoom optical system, the following effects a to d are obtained.
[0040]
a. Each optical member is fixed to each moving base on the side of the optical axis where the emitted light of one optical member becomes the incident light of the other optical member, and the reference guide rail of each moving base is made common, This guide rail was disposed in the vicinity of the optical axis.
[0041]
As a result, the adverse effect on the image quality caused by the expansion and contraction of the optical member due to the temperature change and the change of the refractive power due to this can be eliminated.
[0042]
b. By fixing the respective optical members to the respective moving bases at one end thereof and on the optical axis side, the adverse effect on the image quality can be similarly eliminated.
[0043]
c. When the thermal expansion coefficient of the optical member is close to the thermal expansion coefficient of the moving base to which the optical member is attached, the mounting position of one optical member to the first moving base and the second moving base to the second moving base Similarly, the adverse effect on the image quality can be eliminated by setting the mounting positions of the other optical members symmetrically with respect to the common reference guide.
[0044]
d. The fixed position of the first optical member that does not move to the base and the fixed positions of the moving second and third optical members to the first and second moving bases are also arranged on the reference guide rail side. Similarly, the adverse effect on image quality could be eliminated.
[0045]
(Example 2)
7 and 8 are a plan view and a side view of the “imaging device” according to the second embodiment. 7 and 8 correspond to FIGS. 2 and 3 of the first embodiment, respectively. In the first embodiment, the second optical member 2 and the third optical member 3 are moved using the stepping motors (6, 19) and the screws (7, 20). Furthermore, the arrangement of the stepping motor is also changed. This is done in order to increase the space efficiency more than in the first embodiment, and in particular to reduce the thickness of the mechanical structure. Moreover, the attachment method of the 2nd, 3rd optical member is also changed. In the figure, the same members as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted.
[0046]
Reference numeral 1 denotes a first optical member (same as 1 in FIG. 1), 102 denotes a second optical member (corresponding to 2 in FIG. 1). The difference from the first embodiment is that the first optical member 1 In addition, a mounting portion 102h is provided at one end thereof. This is because the stress caused by tightening at the time of screwing does not adversely affect the optical performance. As described above, the shape is further improved. A mounting portion 102h is formed in an elliptical shape (see FIG. 8). The mounting portion 102h is screwed to the rising portion 105f of the first moving base 105 (corresponding to 5 in FIG. 1) with screws 150 and 150.
[0047]
Another example as shown in FIG. 9 is also conceivable as an attachment shape that does not adversely affect a portion that requires optical performance. In FIG. 9, reference numeral 202 denotes a third embodiment of the second optical member. Reference numeral 202h denotes a mounting portion provided at one end of the optical member 202 as in the case of 102h, but grooves 202i and 202i are provided instead of the slit portion 102i as a relief portion of the tightening stress. In the embodiment of FIG. 9, the mold can be removed in the F and G directions in the figure. In other words, the mold structure is taken into consideration. The first optical member 1, the second optical member 2, and the third optical member 3 in FIG. 1 are similarly shaped in consideration of the mold structure. Further, in this embodiment, one end portion in the longitudinal direction of the optical member is projected to be an attachment portion, but in order not to adversely affect the optical performance due to the tightening stress, the position away from the refractive surface or the reflection surface of the optical member, A similar effect can be obtained by a structure in which the mounting portion is attached to the fixed member by projecting the mounting portion in a direction orthogonal to these surfaces, specifically in FIG.
[0048]
Returning to FIG. 7, reference numeral 103 denotes a third optical member (corresponding to 3 in FIG. 1), which is provided with a mounting portion 103 h and slit portions 103 i, 103 i, 103 i, 103 i (not shown) as in the second optical member 102. It has been. Then, the second moving base 118 is screwed to the rising portion 118 f with screws 151 and 151. Note that the mounting portions of both the second optical member 102 and the third optical member 103 are provided on the first guide rail 15 side as a reference. This is because the expansion and contraction due to the temperature are taken into consideration as in the first embodiment.
[0049]
Furthermore, in this embodiment, the position where the second optical member 102 is screwed to the first moving base 105 and the position where the third optical member 103 is screwed to the second moving base 118 are the first in FIG. The guide rails 15 are almost symmetrical positions (positions where the distances from the guide rails 15 are also substantially equal). This is a consideration for preventing the optical performance from adversely affecting expansion and contraction due to temperature changes when both the optical member and the moving base have substantially the same thermal expansion coefficient, for example, when the material is a plastic material. Specifically, the second optical member 102 will be described below as an example.
[0050]
For example, when the temperature rises, the first moving base 105 shifts in the direction D in the drawing due to expansion of the mounting portion 105f with respect to the first guide rail 15. However, the second optical member 102 shifts in the C direction (the direction opposite to the D direction) in the figure due to expansion with the mounting portion 102h as a reference. In other words, the optical axes 2 f to 3 b (light emitted from the second optical member 102 and light incident on the third optical member 103) are substantially true of the first guide rail 15 because they expand in the direction of canceling each other. You will always keep the top position. Even when the temperature decreases and contracts, the optical axes 2f to 3b do not deviate from the position directly above the first guide rail 15 because the contraction occurs in the direction of canceling each other. The same applies to the relationship between the third optical member 103 and the second moving base 118. As a result, the optical axis emitted from the second optical member 102 is always incident on a certain place on the incident light surface of the third optical member 103, and the optical performance is not deteriorated.
[0051]
Both the second optical member 102 and the third optical member 103 are provided with protrusions 102g, 102g, 102g and 103g, 103g, 103g on the lower surfaces thereof in FIG. .
[0052]
The reason is as follows.
[0053]
In Example 1, the optical member and the moving base were fixed by adhesion. It is assumed that the optical member is positioned three-dimensionally with a jig and fixed with an adhesive during manufacture. In the present embodiment, for example, if the second optical member 102 is described (because the same applies to the third optical member 103), the accuracy of the protrusions 102g, 102g, 102g is obtained, and this portion is used as a reference for attachment. Because. If it does in this way, after mounting an optical member on a movement base, it will be able to fix to a movement base with sufficient precision only by tightening screws 150 and 150.
[0054]
It should be noted that the positions where the protrusions are provided are stabilized as far as possible when placed on the moving base 105, and are located as far as possible in the longitudinal direction (C, D direction) and also in the short direction (direction perpendicular to the C, D direction) as much as possible. A total of three locations are required at separate locations. Further, if necessary, a receiving surface can be provided on the side of the moving base 105, and the accuracy of this portion can be increased and positioning can be performed with higher accuracy.
[0055]
When the material of the optical member is glass, if the second optical member 102 is described, the protrusions 102g, 102g, and the like in the form without the attachment portion 102h (the same shape as the second optical member 2 of the first embodiment). It is also possible to bond and fix at least one of 102g and 102g. In this case, since the positioning portion is bonded and fixed, it is positioned and fixed with higher accuracy.
[0056]
Reference numeral 106 denotes a first drive motor for moving the second moving base 105 along the first guide rail 15, and a tongue-like cam portion 106c having an elongated hole portion 106a is a shaft portion 120 (FIG. 8). See). The elongated hole portion 106a is structured to engage with an engagement pin 105g provided on the first moving base 105. In FIG. 7, the first drive motor 106 is moved from the alternate long and short dash line P to the alternate long and short dash line Q. By rotating, the first moving base 105 and the second optical member 102 fixed to the first moving base 105 move in the direction B in the drawing. In FIG. 7, cam portions 106c drawn with a two-dot chain line represent respective positions when the drive motor 106 rotates by a predetermined angle.
[0057]
The movement of the second movement base 118 and the third optical member 103 fixed to the second movement base 118 in the direction B or in the opposite direction is performed by the second drive motor 119, but is the same as the first drive motor 106 119. A tongue-shaped cam portion 119c having a long hole portion 119a is coupled to a shaft portion (not shown), and the long hole portion 119a engages with an engagement pin 118g provided on the second moving base 118. Thus, the second moving base 118 and the third optical member 103 can move in the B direction or in the opposite direction. The two-dot chain line cam portion 119c represents each position when the second drive motor 119 rotates by a predetermined angle.
[0058]
Here, the arrangement of the drive motors 106 and 119 in the present embodiment will be described.
[0059]
In FIG. 7, the first drive motor 106 is disposed between the second optical member 102, the third optical member 103, and the CCD 25, and the second drive motor 119 is connected to the first optical member 1 and the first optical member 1. The second optical member 102 and the third optical member 103 are disposed. This is the same arrangement as in the first embodiment, and is intended to save space and reduce the size of the apparatus. However, in the first embodiment, the arrangement of the stepping motors 6 and 19 is simply an arrangement in an empty space in the plan view (FIG. 2). In this embodiment, the drive motors 106 and 119 are arranged so that the motor axis direction is perpendicular to the paper surface of FIG. 7 (in the first embodiment, the axis direction is parallel to the paper surface), and a cam mechanism is employed as the moving mechanism. Thus, the drive motors 106 and 119 were able to be shifted in the direction E in FIG. As a result, the position where the stepping motors 6 and 19 in the first embodiment are disposed becomes an empty space, and by arranging the mounting board in this place, the overall space efficiency is improved, which contributes to further miniaturization. it can. Although the cam mechanism is employed in this embodiment, the same effect can be obtained by using a gear train such as a spur gear or a helical gear to reduce the thickness.
[0060]
As described above, also in this embodiment, the same effect as that of Embodiment 1 can be obtained.
[0061]
【The invention's effect】
As described above, according to the present invention, the light beam is incident on the inside from one refracting surface, configured profile so as to emit from the other refracting surface is repeatedly reflected in multiple reflecting surfaces to the outside is bent A zoom optical system having first, second, and third optical members arranged in sequence, a first moving base that holds and moves the second optical member, and holds the third optical member In the image pickup apparatus including the second moving base that moves in this manner, it is possible to prevent image deterioration caused by expansion and contraction of the optical member due to temperature change and change in refractive power due to this.
[Brief description of the drawings]
FIG. 1 is a perspective view of Example 1. FIG. 2 is a plan view of Example 1. FIG. 3 is a side view of Example 1. FIG. 4 is an explanatory diagram of each member. Illustration of the axis [FIG. 6] Optical path diagram of incident light and reflected light [FIG. 7] Plan view of Example 2 [FIG. 8] Side view of Example 2 [FIG. 9] An example of the shape of the projection of the optical member Figure [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st optical member 2 2nd optical member 3 3rd optical member 5 1st movement base 15 1st guide rail 18 2nd movement base

Claims (2)

The first, second, and third are arranged in order, with the outer shape bent, configured such that the light beam enters the inside from the incident light surface and is repeatedly reflected by the plurality of reflecting surfaces and then exits from the exit light surface. A zoom optical system having an optical member; an image sensor that captures a subject image formed by the zoom optical system; a first movement base that moves while holding the second optical member; and the third A second moving base that holds and moves the optical member, a guide rail that regulates the moving direction of the first and second moving bases, and supports the first optical member, the guide rail, and the imaging element. An imaging device comprising:
The exit light surface of the first optical member and the incident light surface of the second optical member are disposed to face each other, and the exit light surface of the second optical member and the incident light surface of the third optical member are disposed to face each other. And the light emitting surface of the third optical member and the imaging element are arranged to face each other
Matching the emission optical axis of the second optical member and the incident optical axis of the third optical member;
The end of the incident light surface vicinity of the first optical member is supported more on the base in the vicinity of the guide rail,
In the vicinity of the emission optical axis of the second optical member and the incident optical axis of the third optical member, the guide rail is arranged in parallel with these optical axes and supported by the base ,
More held on the first moving base in the guide rail near the ends of the exit light surface vicinity of the second optical member,
The end of the incident light plane near the third optical member is more retained in the second moving base near said guide rail,
An imaging apparatus characterized by that. The first, second, and third are arranged in order, with the outer shape bent, configured such that the light beam enters the inside from the incident light surface and is repeatedly reflected by the plurality of reflecting surfaces and then exits from the exit light surface. A zoom optical system having an optical member; an image sensor that captures a subject image formed by the zoom optical system; a first movement base that moves while holding the second optical member; and the third A second moving base that moves while holding the optical member, a guide rail that regulates a moving direction of the first and second moving bases, and supports the first optical member, the guide rail, and the imaging element. An imaging device comprising:
The exit light surface of the first optical member and the incident light surface of the second optical member are disposed to face each other, and the exit light surface of the second optical member and the incident light surface of the third optical member are disposed to face each other. And the light emitting surface of the third optical member and the image sensor are arranged to face each other,
The emission optical axis of the second optical member and the incident optical axis of the third optical member are matched,
The end of the incident light surface vicinity of the first optical member is supported more on the base in the vicinity of the guide rail,
In the vicinity of the exit optical axis of the second optical member and the incident optical axis of the third optical member, the guide rail is arranged in parallel with these optical axes and supported by the base,
The end of the incident light surface vicinity of the first optical member is supported more base in the vicinity of the guide rail,
The end of the exit light surface vicinity of the second optical member, at the exit light side of the viewed from the guide rail third optical member, and more held in the first moving base,
The end of the incident light surface vicinity of said third optical member, at the exit light side of the viewed from the guide rail first optical member, and more held in the second moving base,
A holding position of said second optical member in the first moving base, the second and the holding position of the third optical member in a mobile base and a position axisymmetric with respect to the guide rail,
An imaging apparatus characterized by that.

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