JP2003037758A - Imaging unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging unit that is low-cost and yet has reduced number of components, can be made small, assembled with high accuracy in spite of being unadjusted, and has a dustproof and moisture-proof structure with high reliability. SOLUTION: Since an elastic member 6 presses a leg portion 1c into contact with a surface of an imaging device 2b, directed in a lens section 1a with a prescribed elastic force, even though the alignment between an optical member 1 and the imaging devices 2b in an optical axis direction is facilitated, even when deformation such as a bent takes place in components due to a change over time, the elastic member 6 energizes the optical member 1 to the imaging devices 2b with a stable elastic force, so as to suppress plays in the optical member 1 on the occurrence of vibration. At the occurrence of shocks, excess stress is not produced in to a peripheral surface 2a of the imaging devices 2b the inside of which a circuit is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device,
Especially mobile phones and personal computers (personal computers)
The present invention relates to an image pickup device that can be installed in, for example.

[0002]

2. Description of the Related Art In recent years, it has become possible to easily handle digital image data due to improvements in CPU performance and image processing technology. Especially mobile phones and P
In DA, a model equipped with a display capable of displaying an image is available on the market, and a dramatic improvement in wireless communication speed can be expected in the near future.
It is expected that image data will be frequently transferred between DAs.

By the way, at present, after converting a subject image into image data with a digital still camera or the like, such image data is transferred via the Internet via a personal computer or the like. However, in such a mode, in order to transfer image data, it is necessary to have both a digital still camera and a personal computer. On the other hand, there is an attempt to mount an image pickup device such as a CCD type image sensor on a mobile phone.
According to such an attempt, it is not necessary to own a digital still camera or a personal computer, and it is easy to take an image with a mobile phone that can be easily carried and send it to the other party.

[0004]

However, at present, if the mobile phone has the function of a digital still camera much larger than that of the mobile phone, the mobile phone itself becomes large and heavy, which makes it difficult to carry. There is a problem. In addition, the manufacturing cost increases accordingly.

In particular, even if the photographing optical system, which is a main component of the digital still camera, and the image pickup device are unitized, the photoelectric conversion section of the image pickup device is not properly set at the focus position of the image pickup optical system. The problem is how to make such adjustments. For example, when the image sensor and the photographic optical system are installed on the same substrate, the focus position of the photographic optical system may be affected by factors such as variations in the thickness of the adhesive used to attach the substrate and dimensional variations in the components. It can be said that it is difficult to assemble the photoelectric conversion unit of the image pickup device with high accuracy. Therefore, in order to improve the assembling accuracy of the focusing position of the photographing optical system and the photoelectric conversion unit of the image sensor, a highly accurate assembling technique is required, or a mechanism for separately adjusting the focusing position is required, Then, there is a problem that the manufacturing cost increases. The problems of the prior art will be pointed out by giving examples.

FIG. 6 is a sectional view showing an example of a conventional image pickup device. An image pickup element 110 is arranged on a glass epoxy substrate PC, and a large number of wires W are connected from terminals (not shown) on the upper surface. Then, it is connected to the image processing IC circuit 111 arranged on the back surface of the substrate PC.

A first casing 101 is arranged so as to cover the image pickup device 110, a second casing 102 is placed on the first casing 101, and the second casing 102 is fastened to the substrate with bolts 103.
An infrared cut filter 104 is arranged between the first housing 101 and the second housing 102.

The upper portion of the second housing 102 is cylindrical, and the internal thread 102a formed on the inner surface of the second housing 102 has a male thread 10a.
By screwing 5a, the lens barrel 105 including the lens 106 is attached to the second housing 102 so that the position thereof in the optical axis direction can be adjusted. Lens barrel 105
Has a narrowed portion 105b formed on the upper side.

As described above, the conventional image pickup apparatus is a relatively large-sized apparatus composed of a large number of parts. Therefore, it is troublesome to assemble these parts while avoiding the above-mentioned problem of manufacturing cost. , The image pickup device 110 and the lens 10 while rotating the lens barrel 105.
It is also necessary to adjust the relative position with respect to 6.

In order to solve such a problem, the lens is
There is an attempt to provide an image pickup apparatus by providing a leg portion that extends to the vicinity of the focal length position of a lens and directly contacting the leg portion with the image pickup element. According to such an attempt, the photoelectric conversion unit of the image pickup device can be arranged at the focus position of the lens, and the labor at the time of assembling the image pickup apparatus can be greatly reduced.

However, it is expected that various devices equipped with such a compact image pickup device will be subject to vibrations or shocks when accidentally dropped. In such a case, when the leg portion of the lens is brought into contact with the image pickup element, the lens may be shaken by vibration, or the image pickup element may be damaged by impact.

To solve such a problem, it may be considered that the lens is brought into contact with the image pickup element while applying a predetermined pressure by the lens holder, and the lens holder and the substrate are adhered to fix the lens. Kaihei 9-2846
(See No. 17). According to such a technique, rattling between the lens and the image pickup device can be suppressed, but in the case where the pressure is reduced due to a change in the thickness of the adhesive or the shape of parts,
The lens may rattle. Further, there is still a possibility that the lens may damage the image pickup device due to the impact force.

The present invention has been made in view of the above problems, and it is inexpensive, but the number of parts can be reduced, downsizing can be achieved, and rattling of a lens and damage due to external force can be suppressed for a long period of time. Furthermore, it is an object of the present invention to provide an image pickup apparatus that can be assembled with high precision even without adjustment, has a dustproof and moistureproof structure, and has high reliability.

[0014]

In order to achieve such an object, an image pickup apparatus according to a first aspect of the present invention includes a substrate, a photoelectric conversion section, an image pickup element mounted on the substrate, and the image pickup element. An optical member including a lens unit for forming a subject image on the photoelectric conversion unit provided in, and a leg unit supporting the lens unit, and an elastic unit, and by an elastic force of the elastic unit, The optical member is biased toward the image pickup device.

An image pickup device according to a second aspect of the present invention includes a substrate and a photoelectric conversion unit, and forms an image of a subject on the image pickup device mounted on the substrate and the photoelectric conversion unit provided on the image pickup device. An optical member having a lens portion for allowing the lens portion and a leg portion for supporting the lens portion, and a lens frame having an elastic means for supporting the optical member are provided, and by the elastic force of the elastic means, The optical member is biased toward the image pickup device.

[0016]

According to the first aspect of the present invention, an image pickup device is provided with a substrate and a photoelectric conversion unit, and an object image is formed on the image pickup device mounted on the substrate and the photoelectric conversion unit provided on the image pickup device. An optical member having a lens portion that allows the lens portion and a leg portion that supports the lens portion, and an elastic member, and the elastic member biases the optical member toward the image sensor. Therefore, for example, by abutting and biasing the leg portion of the optical member against the surface of the image sensor, it is possible to easily position the optical member and the image sensor in the optical axis direction, Even when a component such as a warp or the like is deformed due to a change with time, the optical member can be urged against the image pickup element by a stable elastic force, and the vibration is generated when the vibration occurs. By suppressing the rattling of optical components , Yet it is possible to suppress the damage of the image pickup device at the time of impact has occurred. In addition, as the image pickup device, a CMOS (ComplementaryM) is used.
etal Oxide Semiconductor)
Type image sensor is suitable, but CCD (Char
The image sensor may be a gaged coupled device type image sensor.

Further, by the elastic force of the elastic means, the leg portion is in contact with the surface of the image pickup element facing the lens portion with a load of 5 g or more and 500 g or less,
By properly managing the elastic force, damage to the image pickup device can be suppressed.

If a cover member that is attached to a lens frame fixed to the substrate, is arranged closer to the subject than the lens portion, presses the elastic means, and at least a part of which is transparent to light, It is possible to protect the lens portion. That is, since the lens member is not exposed to the outside due to the cover member, and the impact from the outside to the cover member is absorbed by the elastic member, a strong impact is applied to the lens unit. As a result, it is possible to prevent the image sensor from being damaged.

Further, when the elastic means is formed separately from the optical member and the cover member, only the elastic means needs to be replaced when managing the elastic force, and the cost can be reduced. . Here, the term “separate body” means that each member is composed of individual independent members, is not integrated by an adhesive or the like, and can be handled as an individual component when removed.

If the elastic means is a coil spring,
Can exert elastic force stably for a long period of time.

Further, if the elastic means is a sheet-like member having an opening at the center, it is easy to assemble and it is preferable in terms of space saving.

Further, the sheet-like member is made of a light-shielding member, and if it also has a function of a diaphragm for defining the F number of the lens portion, it is not necessary to separately provide a diaphragm, and the number of parts can be reduced. Therefore, it is preferable.

On the other hand, it is preferable that the elastic means is integrated with the cover member because the number of parts can be reduced.

Further, it is preferable that the elastic means is integrated with the optical member because the number of parts can be reduced.

An image pickup apparatus according to a second aspect of the present invention includes a substrate and a photoelectric conversion unit, and an object image is formed on the image pickup device mounted on the substrate and the photoelectric conversion unit provided on the image pickup device. An optical member having a lens portion for allowing the lens portion and a leg portion for supporting the lens portion, and a lens frame having an elastic means for supporting the optical member are provided, and by the elastic force of the elastic means, Since the optical member is biased toward the image pickup device, for example, the leg portion of the optical member is brought into contact with the surface of the image pickup device and biased so that the light of the optical member and the image pickup device is increased. Despite the ease of axial positioning, the elastic member biases the optical member against the image sensor with a stable elastic force even when a component such as a warp is deformed due to a change over time. When the resulting vibration Definitive wherein it is possible to suppress the rattling of the optical member, yet it is possible to suppress the damage of the image pickup device at the time of impact has occurred.

Further, due to the elastic force of the elastic means, the leg portion is in contact with the surface of the image pickup element facing the lens portion with a load of 5 g or more and 500 g or less,
By properly managing the elastic force, damage to the image pickup device can be suppressed.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of the image pickup apparatus according to the present embodiment. FIG. 2 is a perspective view of the image pickup apparatus of FIG. FIG. 3 is a perspective view of an optical member,
FIG. 4 is a bottom view of the optical member. FIG. 5 is a top view of the image sensor.

The optical member 1 is made of a plastic material, and the lens portion and the leg portion are integrally formed as shown in FIG. More specifically, the optical member 1 has a tubular leg portion 1.
c, four contact portions 1d formed at the lower end of the leg portion 1c as a part thereof, a step portion 1e formed around the upper end of the leg portion 1c, and a plate-like upper surface that closes the upper end of the leg portion 1c. The portion 1b and the convex lens portion 1a formed in the center of the upper surface portion 1b are integrally formed. In addition, on the upper surface of the upper surface portion 1b and around the convex lens portion 1a, a light-shielding material is used.
A diaphragm plate 3 having an opening 3a as a first diaphragm that defines the F number of the convex lens portion 1a is fixed by adhesion or the like.

On the outer side of the optical member 1, a lens frame 4 made of a light-shielding material is arranged. As is apparent from FIG. 2, the lens frame 4 has a prismatic lower portion 4a and a cylindrical upper portion 4a.
b and are provided. The lower end of the lower portion 4a is in contact with the substrate PC and is fixed by the adhesive B. The upper surface of the lower portion 4a is covered with the partition wall 4c on the peripheral side, and the leg portion 1c of the optical member 1 is closely fitted to the circular inner peripheral surface of the partition wall 4c. Therefore, the substrate PC and the lens frame 4 are attached to the center of the circular opening of the partition wall 4c and the image pickup device 2 described later by using, for example, an optical sensor (not shown) provided in the automatic assembly machine.
The photoelectric conversion unit 2b of the image pickup device 2b, which will be described later, can be simply arranged by positioning so that the centers of the photoelectric conversion units 2d of b.
The lens portion 1a can be accurately positioned with respect to d in the direction orthogonal to the optical axis.

On the other hand, a light shielding plate 5 is attached by an adhesive B to the upper end of the upper portion 4b of the lens frame 4. Light shield 5
Has an opening 5a as a second diaphragm in the center thereof. Below the opening 5a of the light shielding plate 5, a filter 7 made of a material having an infrared absorbing property is attached by an adhesive agent B. The light shielding plate 5 and the filter 7 form a cover member.

In FIG. 1, an elastic means 6 composed of a coil spring is arranged between the light shield plate 5 and the step portion 1e of the optical member 1, and the light shield plate 5 is elastically deformed by being attached to the lens frame 4. However, the elastic force presses the optical member 1 downward in FIG. Therefore, the force from the light shielding plate 5 is transmitted to the substrate PC via the lens frame 4, but is not directly transmitted to the image pickup element 2b.

In FIG. 5, the image pickup unit 2 is a CMO.
It is composed of an image sensor 2b such as an S-type image sensor. The lower surface of the rectangular thin plate-shaped image sensor 2b is attached to the upper surface of the substrate PC. A photoelectric conversion unit 2d in which pixels are two-dimensionally arranged is formed in the center of the upper surface of the image sensor 2b, and an image processing circuit is formed inside and inside the image sensor 2b around the photoelectric conversion unit 2d. A surrounding surface 2a is formed. Peripheral surface 2 that intersects perpendicularly to the thin side surface
A large number of pads 2c are arranged near the outer edge of a. The pad 2c, which is a connection terminal, is connected to the substrate PC via the wire W as shown in FIG. The wire W is connected to a predetermined circuit on the substrate PC.

Further, the contact portion 1d of the optical member 1 has a shape as shown in FIG. 4 and protrudes from the lower end of the leg portion 1c, and the leg portion 1c.
It constitutes a part of. In the present embodiment, FIG.
As indicated by the dotted line, on the peripheral surface 2a of the image sensor 2b, only the contact portion 1d is arranged inside the pad 2c so as to be in contact. Therefore, regarding the surface flatness, it is sufficient if only the lower surface of the contact portion 1d is maintained within a predetermined range. Further, since there are four leg portions 1c (contact portions 1d) and the center of gravity of the optical member 1 is at the center thereof, when the optical member 1 is placed alone on a plane, the optical axis of the lens portion 1a is Can be said to have a position and a shape that are orthogonal to the plane. Therefore, even if there is a gap between the inner peripheral surface of the lens frame 4 and the outer peripheral surface of the optical member 1, the peripheral surface 2 of the image sensor 2b is
When the leg portion 1c is brought into contact with a, the optical axis is orthogonal to the photoelectric conversion portion 2d of the image sensor 2b, and an image with less distortion can be obtained. Here, a circuit (including a signal processing circuit) (not shown) of the image sensor is provided on the back side of the peripheral surface 2a (the lower surface side in FIG. 1), but the circuit processing is performed by the contact of the contact portion 1d. Is not affected.

Here, in considering the contact position of the contact portion 1d, for example, in the corner portion 2g of the surface of the photoelectric conversion portion 2d shown in FIG. 5, the effective pixel area is set to be slightly smaller than the entire pixel area. By doing so, it becomes an area unrelated to image formation,
In such a case, even if the contact portion 1d is brought into contact with the area of the corner 2g even within the surface of the photoelectric conversion portion 2d, the image pickup device 2b is provided.
It can be said that there is little fear of affecting the image pickup performance of. still,
Whichever region of the peripheral surface 2a or the surface of the photoelectric conversion unit 2d is brought into contact, the load from the contact portion 1d is preferably 500 g or less. This is because if the load is exceeded, the image sensor 2b may be damaged. However, considering the blurring of the image due to vibration, etc., the contact portion 1
The load from d is preferably 5 g or more. The load is applied to the coil spring 6 which is an elastic means as described later.
Appropriate management can be achieved by selecting the wire diameter, number of turns, and so on. Further, in any load of 5 g or more and 500 g or less, it is more preferable that the surface pressure is 1000 mg / mm ² or less in order to prevent damage to the image pickup element due to a local extreme load. Here, the surface pressure is obtained by dividing the load applied to the image pickup element through the leg portion (contact portion 1d) of the optical member by the area of the surface facing the lens portion with which the leg portion is in contact. It is a thing.

According to the present embodiment, the optical member 1 is contacted with the contact portion 1d in contact with the peripheral surface 2a of the image pickup element 2b.
Since a gap Δ is formed between the lower surface of the step portion 1e and the partition wall 4c of the lower portion 4a of the lens frame 4,
The distance L (that is, the positioning in the optical axis direction) between the lens portion 1a and the photoelectric conversion portion 2d of the image pickup element 2b is set accurately by the length of the leg portion 1c. Although four contact portions are provided in this embodiment, one to three contact portions are provided.
It can be in several places. Further, if interference with the pad 2c can be avoided, along the cylindrical leg portion 1c of the optical member 1,
It may be a ring-shaped contact portion.

Further, since the optical member 1 is made of a plastic material, it is possible to reduce the shift of the focusing position due to the change in the refractive index of the lens portion when the temperature changes. That is, as the plastic lens rises in temperature,
The refractive index of the lens decreases, and the focus position changes in the direction away from the lens. On the other hand, since the leg portion 1c extends due to the temperature rise, it has the effect of reducing the focus position shift. Since the optical member 1 of the present embodiment is made of a plastic material having a relatively light specific gravity, it is lighter in weight than glass even in the same volume and has excellent shock absorption characteristics. Even in such a case, there is an advantage that damage to the optical member 1 and the image pickup device 2b with which the optical member 1 is brought into contact can be suppressed as much as possible.

Further, as shown in FIG. 5, when the optical member 1 has a structure capable of rotating freely within the lens frame 4, the contact portion 1d interferes with the pad 2c, so that the rotation is restricted. A structure to be assembled (for example, a rotation stopper is provided on the lens frame 4) is preferable.

The operation of this embodiment will be described. The lens portion 1a of the optical member 1 captures a subject image with the image sensor 2b.
An image is formed on the photoelectric conversion unit 2d. The image pickup device 2b is adapted to convert an electric signal corresponding to the amount of received light into an image signal or the like and output it via the pad 2c and the wire W.

Further, in this embodiment, the optical member 1 is not mounted on the substrate PC, but the image pickup device 2b.
Since it is mounted on the peripheral surface 2a of the optical member 1, by controlling the dimensional accuracy of the leg portion 1c (including the contact portion 1d) of the optical member 1, that is, the accuracy of the distance L described above, the lens portion 1a can be assembled. It is possible to eliminate the need for adjusting the focus position of. Since the image pickup apparatus according to the embodiment of the present invention does not have a focus adjustment mechanism according to the subject distance, the lens of the image pickup apparatus is focused from a long-distance subject to a short-distance subject.
Must be a pan focus lens. Therefore, the image point position of the lens unit 1a at the hyperfocal length U≈f ² / (F × 2P) (where f is the focal length of the lens, F is the F number of the lens, and P is the pixel pitch of the image sensor). By matching the position in the optical axis direction with the photoelectric conversion unit 2d of the image pickup device 2b, geometrically optics can be performed at a distance of U / 2 from infinity.
The object at a distance of can be regarded as being in focus. For example, f = 3.2 mm, F = 2.8, P = 0.0
For 056Mm, as a reference object distance, the image point position of the lens portion 1a in the hyperfocal distance U ≒ ^f 2 /(F×2P)=0.33m, the optical axis direction of the photoelectric conversion unit 2d of the image pickup element 2b If the above-mentioned distance L is set so that the positions coincide with each other, the state is in focus from infinity to a distance of about 0.17 m. Further, it is not always necessary to set the hyperfocal length as the reference subject distance. For example, when it is desired to focus on the image quality at a longer distance, the reference subject distance may be set farther than the hyperfocal length (specifically, the above-mentioned Distance L
Should be slightly shorter. ). Here, in terms of the accuracy of the distance L, in order to eliminate the need for adjusting the in-focus position as the pan focus lens, the photoelectric conversion unit 2d of the imaging device 2b is used.
And the deviation in the optical axis direction of the image point at the reference object distance of the lens unit 1a is ± 0.5 × (F × 2P) in air conversion length.
(F: F number of taking lens, P: pixel pitch of image sensor) need to be suppressed. Also, preferably ±
It is preferable to suppress it to about 0.25 × (F × 2P). If this deviation is large, the image quality at infinity or at a close range is deteriorated, which is not preferable.

Further, according to the present embodiment, the contact portion 1d of the leg portion 1c of the optical member 1 abuts on the peripheral surface 2a of the image pickup element 2b, so that the photoelectric conversion of the lens portion 1a and the image pickup element 2b is performed. Positioning with the portion 2d in the optical axis direction can be performed.
Further, the lens frame 4 is provided on the substrate PC on the photoelectric conversion unit 2 of the image pickup device 2b.
The lens unit 1 is installed by using d as a positioning reference.
Since the positioning of a and the photoelectric conversion unit 2d of the image pickup device 2b is performed in the direction orthogonal to the optical axis, it is possible to achieve high positioning accuracy at low cost.

Particularly, when the pad 2c and the wire W for connecting the image pickup device 2b and the substrate PC are formed on the peripheral surface 2a of the image pickup device 2b, the contact portion 1d of the leg portion 1c is If it is configured so as to contact the peripheral surface 2a on the photoelectric conversion portion 2d side of the pad 2c, the image pickup device 2b
While maintaining a compact structure, a large contact area of the contact portion 1d can be secured, thereby stabilizing the optical member 1 and suppressing the surface pressure of the contact surface to a low level. Pad 2c while protecting 2b
The interference with the wire W and the wire W is suppressed, and highly accurate positioning is achieved. It should be noted that the lens frame 4 is adhered to the substrate PC and, together with the other two adhering portions, is kept in a sealed state so that foreign matter does not enter the outside of the image pickup apparatus. The adverse effect of foreign matter on the photoelectric conversion unit 2d of 2b can be eliminated. The adhesive used for these preferably has moisture resistance. As a result, it is possible to prevent surface deterioration of the image pickup device and the pad due to invasion of moisture.

Further, since the elastic means 6 for pressing the step portion 1e of the optical member 1 in the optical axis direction with a predetermined elastic force is provided, the elastic force of the elastic means 6 is used to the lens frame 4. The leg portion 1c (contact portion 1d) can be pressed against the peripheral surface 2a of the image sensor 2b with an appropriate contact force (a force corresponding to the load of 5 g or more and 500 g or less described above) along the optical axis direction. Therefore, although the optical member 1 and the image pickup device 2b can be easily positioned in the optical axis direction, even if the components such as warp are deformed due to a change with time, the optical member 1 has a stable elastic force. 1 can be urged against the image pickup device 2b, thereby suppressing the rattling of the optical member 1 when vibration occurs, and further, when a shock occurs, the circuit is arranged inside. Excessive strike on the peripheral surface 2a of the image sensor 2b It is not possible to generate a scan. Further, even when a large force such as an impact force is applied in the optical axis direction of the lens frame 4, the force is transmitted to the substrate PC via the lens frame 4, but is not directly transmitted to the image sensor 2b. Without
It is preferable from the viewpoint of protection of the image sensor 2b. The elastic means 6 may be urethane or sponge, but is preferably a metal spring or the like that can exhibit a stable elastic force for a long period of time.

Further, since the cover member composed of the light shielding plate 5 and the filter 7 is arranged closer to the subject side than the lens portion 1a, the lens portion 1a can be protected without being exposed and the lens surface can be protected. It is possible to prevent foreign matter from adhering to the surface. Furthermore, since the filter 7 is formed of a material having an infrared absorption characteristic, it is not necessary to separately provide an infrared cut filter, and the number of parts can be reduced, which is preferable. Instead of providing the filter 7 with the infrared cut property, the optical member 1 itself may be formed of a material having the infrared absorption property, or the surface of the lens 1a may be coated with a film having the infrared cut property.

Further, at the time of assembly, the optical member 1 can be inserted into the lens frame 4 from the subject side with the light shield plate 5 removed from the lens frame 4, and then the light shield plate 5 is attached. 4 can be assembled. With such a configuration, the assembling property of the optical member 1 is improved, and automatic assembly or the like can be easily performed. At this time, if an air escape hole is formed in any of the lower portions 4a of the lens frame 4, the lens frame 4
Even if there is a slight gap between the optical member 1 and the optical member 1, the assembly can be easily performed. However, such air escape holes can be sealed with a filler after assembly,
It is preferable to prevent foreign matter from entering from the outside and surface deterioration of the image sensor and the pad due to moisture. Also,
In such a case, the filler preferably has a light shielding property so as to suppress light leakage. It should be noted that the optical member 1 may be inserted after the lens frame 4 is adhered to the substrate PC, or after the optical member 1 is attached to the lens frame 4, the unit-by-unit substrate PC
It may be adhered to the base material, which ensures process flexibility. In the case of the latter assembling procedure, the partition wall 4c of the lens frame 4 can also have a function of preventing the optical member 1 from slipping off.

Since the leg portion 1c of the optical member 1 is arranged near the photoelectric conversion portion 2d of the image pickup device 2b, a light beam which does not contribute to image formation is reflected by the leg portion 1c and is incident on the photoelectric conversion portion 2d. This may cause ghosts and flares. In order to prevent this, a second diaphragm (aperture 5a) that regulates peripheral light flux is arranged on the object side of the first diaphragm (aperture 3a) that defines the F number of the lens unit 1a, and unwanted light is incident. Is effective. Since the angle of view differs depending on the short side / long side of the photoelectric conversion unit 2d of the image pickup device 2b and the diagonal direction, a further effect can be obtained by making the opening 5a of the second diaphragm rectangular. Further, in the present embodiment, the opening 5a of the light shielding plate 5 is provided with this function. However, the subject side of the filter 7 is coated or coated with a light shielding film at a portion other than the required opening portion to reduce the aperture. May be formed. Also, for the same reason,
It is preferable that at least a part of the leg portion 1c be subjected to an inner surface antireflection treatment. The inner surface antireflection treatment includes, for example, forming a surface provided with minute unevenness so as to scatter a light flux that does not contribute to image formation, and applying an antireflection coating or a paint having a low reflection property.

Further, since the diaphragm plate 3 having the opening 3a is provided on the incident surface side of the lens portion 1a, the light beam incident on the light receiving surface 2d of the image pickup device 2b is made incident at an angle close to vertical.
That is, it can be close to telecentric, whereby a high quality image can be obtained. Further, the shape of the lens portion 1a is the shape of a positive lens with a surface having a strong curvature facing the image side, whereby the first diaphragm (opening 3
The distance between a) and the principal point of the lens portion 1a can be widened, and a desirable configuration closer to telecentricity can be obtained. In this embodiment, the lens portion 1a has a positive meniscus shape with the convex surface facing the image side. Further, in order to obtain a higher quality image, it is preferable that the lens portion is composed of a plurality of lenses as in the third embodiment described later.

FIG. 7 is a sectional view of an image pickup apparatus including a modification of the elastic means, and FIG. 8 is a perspective view showing the optical member and the elastic means in a disassembled state. The elastic means 16 of FIG.
It is made of a light-shielding material and has a diaphragm function instead of the diaphragm plate 3 shown in FIG. More specifically, as apparent from FIG. 8, the elastic means 16 made of resin is a substantially disk-shaped sheet-like member having an opening (aperture) 16a in the center, and is arranged at equal intervals from the circumference. Four protrusions 16b project outward in the radial direction.
On the other hand, the ring portion 11f formed on the top of the optical member is
A notch 11g is formed corresponding to the protrusion 16b.
By engaging the protrusion 16b with the notch 11g, the elastic means 16 is fitted in the ring portion 11f in a fitting manner. Furthermore, when the light shield plate 15 is attached, each protrusion 16 is formed by the protrusion 15c formed on the lower surface thereof.
When b is pressed from above, the protrusion 16b elastically deforms,
The optical member 11 is applied to the peripheral surface 2 of the image sensor 2b with a predetermined elastic force.
It is designed to urge against a. The other configurations are similar to those of the embodiment shown in FIG.

FIG. 9 is a diagram showing an image pickup apparatus according to the second embodiment. The second embodiment is different from the above-described embodiment only in that the configurations of the diaphragm plate and the light shielding plate are changed, and therefore, the same reference numerals are given to the other similar configurations and the description will be given. Omit it.

In FIG. 9, a holding member 5'having a thin light shielding sheet 8 attached to the upper surface of the upper portion 4b of the lens frame 4 is attached.
Are attached by an adhesive B. In the central opening 5a 'of the holding member 5'made of a light-shielding material,
A filter 7'made of a material having an infrared absorption characteristic is fitted and arranged. A taper surface 5b 'is formed on the upper edge of the opening 5a' of the holding member 5 ', and the adhesive B
By attaching the, the holding member 5'and the filter 7'can be joined. Furthermore, the holding member 5 '
Is provided with a diameter-reduced portion 5c 'which projects downward from the opening 5a' and whose inner diameter is gradually reduced, and the most narrowed portion at the lower end thereof constitutes a first aperture 5d '. Further, the central opening 8a of the light shielding sheet 8 constitutes a second diaphragm. The holding member 5 ′, the filter 7 ′, and the light shielding sheet 8 form a cover member.

According to this embodiment, the cover member composed of the holding member 5 ', the filter 7'and the light shielding sheet 8 is
Since the optical member 1 is arranged closer to the subject side than the lens portion 1a, the lens portion 1a can be protected without being exposed, and foreign matter can be prevented from adhering to the lens surface. Further, since the cover member can be integrally formed, it contributes to reduction of the number of parts of the entire image pickup apparatus.

As in the above-described embodiment, the leg portion 1c of the optical member 1 is arranged near the photoelectric conversion portion 2d of the image pickup device 2b, so that a light beam that does not contribute to image formation is reflected by the leg portion 1c. However, there is a concern that ghost and flare may occur when the light enters the photoelectric conversion unit 2d. In the present embodiment, the second diaphragm (aperture 8a) that regulates the peripheral light flux is arranged on the subject side of the first diaphragm 5a 'that defines the F number of the lens unit 1a to reduce the incidence of unnecessary light. ing. Since the angle of view differs depending on the short side / long side and the diagonal direction of the photoelectric conversion unit 2d of the image pickup device 2b, the aperture 8 of the second diaphragm is formed.
By making a rectangular, a further effect can be obtained.

Further, also in this embodiment, the step portion 1e of the optical member 1 is pressed in the optical axis direction by a predetermined elastic force.
Since the elastic means 6 as the urging member is provided, the leg portion 1c (contact portion 1d) is attached to the imaging element along the optical axis direction with respect to the lens frame 4 by using the elastic force of the elastic means 6. It can be pressed against the peripheral surface 2a of 2b with an appropriate contact force (contact force of 5g or more and 500g or less as described above), and therefore excessive stress is generated on the peripheral surface 2a of the image pickup device 2b in which the circuit is arranged inside. The optical member 1 does not rattle due to vibration.

FIG. 10 is a sectional view of an image pickup apparatus including another modification of the elastic means. The elastic means 26 of FIG. 10 is integrated with a holding member, that is, a cover member. As is apparent from FIG. 10, the holding member 26 is made of a resin material such as an elastomer resin that is easily elastically deformed, the elastic means 6 of FIG. 9 is removed, and the holding member 5 ′ of FIG. 4 (only two shown) protrusions (elastic means) 2
The only difference is that 6e is formed. By fixing the holding member 26 to the lens frame 4 with the adhesive B and elastically deforming the protrusion 26e, the optical member 1 is urged against the peripheral surface 2a of the image sensor 2b with a predetermined elastic force. ing. The other structure is similar to that of the embodiment shown in FIG.

FIG. 11 is a diagram showing an image pickup apparatus according to the third embodiment. The third embodiment is different from the embodiment of FIG. 2 mainly in that the configuration of the optical member is changed so as to have a plurality of lens portions, so that the contact between the leg portion and the image sensor is achieved. With respect to other similar configurations including positions, the same reference numerals are given and description thereof is omitted.

In FIG. 11, the optical member 19 is composed of an image side lens 1 ′ and a subject side lens 9 each made of a plastic material. The image-side lens 1'has a shape similar to that of the optical member 1 shown in FIG. 1, but the height of the ring portion 1f 'formed on the upper side in the optical axis direction is increased. The inner surface of the ring portion 1f ′ in the radial direction and the upper surface portion 1
A subject-side lens 9 is arranged above b ′ via a diaphragm plate 3 that defines the F number. The subject side lens 9 has a flange portion 9b fitted to the inner circumference of the ring portion 1f '.
And a lens portion 9a formed in the center. The lens portion 1a 'of the image side lens 1'is a positive lens, whereas the lens portion 9a of the subject side lens 9 is a negative lens. In the present embodiment, the diaphragm plate 3
Serves as a spacer that regulates the distance between lenses of the lens portions 1a ′ and 9a, and the opening 3a of the diaphragm plate 3 functions as a first diaphragm that regulates the F number.

The inner peripheral surface of the ring portion 1f ′ of the image side lens 1 ′ and the outer peripheral surface of the flange portion 9b of the subject side lens 9 are
Since they have the same diameter as each other and are parallel to the optical axis, the lens portions 1a ′, 9
Positioning of a in the direction orthogonal to the optical axis can be performed, and those optical axes can be easily matched. The subject side lens 9 is bonded to the image side lens 1'by an adhesive B applied to the periphery thereof.

On the upper end of the upper portion 4b of the lens frame 4, a holding member 5'having a thin light-shielding sheet 8 attached on its upper surface is attached by an adhesive B. A filter 7'made of a material having an infrared absorbing property is fitted and arranged in an opening 5a 'at the center of a holding member 5'made of a light-shielding material. At the upper edge of the opening 5a 'of the holding member 5', the tapered surface 5
b'is formed, and by attaching the adhesive B thereto, the holding member 5'and the filter 7'can be joined. Further, the holding member 5 ′ has a reduced diameter portion 5 that protrudes downward of the opening 5a ′ and has a gradually reduced inner diameter.
Although c'is provided, such a portion functions as a light shielding portion that suppresses intrusion of unnecessary light. The central opening 8a of the light shielding sheet 8 constitutes a second diaphragm.

Further, also in the present embodiment, since the elastic means 6 as a biasing member for pressing the step portion 1e 'of the optical member 19 in the optical axis direction with a predetermined elastic force is provided, such elasticity is obtained. By using the elastic force of the means 6, the leg portion 1c ′ (contact portion 1d ′) is appropriately contacted with the peripheral surface 2a of the image sensor 2b along the optical axis direction with respect to the lens frame 4 (5g described above). Above 5
It can be pressed with a contact force of 100 g or less), so that the surrounding surface 2a of the image pickup device 2b having the circuit inside is not excessively stressed, and the optical member 19 is prevented from rattling due to vibration. Has become.

FIG. 12 is a perspective view of another modification of the elastic means. The elastic means 36 of FIG. 12 is integrated with the optical member, and can be incorporated in the image pickup apparatus of FIG. 1 in which the elastic means 6 is omitted, for example. As is clear from FIG. 12, the optical member 36 is different from the optical member 1 of FIG.
On the step portion 36e, four protrusion portions (elastic means) 36f at equal intervals and an arm portion 36g for supporting the protrusion portions 36f.
The only difference is the formation of. In the state where the optical member 36 is assembled as shown in FIG. 1, the protrusion 36g comes into contact with the lower surface of the light shielding plate 5 (FIG. 1), which elastically deforms the cantilevered arm 36g. The generated elastic force urges the optical member 1 against the peripheral surface 2a of the image pickup device 2b with a predetermined elastic force (FIG. 1). The other configurations are similar to those of the embodiment shown in FIG.

FIG. 13 is a sectional view of an image pickup apparatus including still another modification of the elastic means. The elastic means shown in FIG. 13 is integrated with the lens frame. As is apparent from FIG. 13, the lens frame 46 has four notches 46d (only two are shown) formed at equal intervals in the upper half portion 46b of the lens frame 4 of FIG. The lower end of the arm 46e extending parallel to the optical axis is connected to the lower edge of the notch 46d in FIG. Arm 4
At the upper end of 6e, a protrusion 46f having a substantially triangular cross section is formed so as to protrude inward in the direction perpendicular to the optical axis. The upper portion of the step portion 1e of the optical member 1 is preferably tapered as shown in FIG. The arm 46e and the projection 46f constitute an elastic means.

In the lens frame 46 attached to the substrate PC,
When the optical member 1 is inserted from above in FIG.
Since the stepped portion 1e contacts the 6f and elastically deforms the arm 46e so as to push it outward in the direction perpendicular to the optical axis, the optical member 1 can be easily incorporated. On the other hand, when the optical member 1 is assembled up to the position shown in FIG.
Although the deformation of 6e is restored, the shape of the protrusion 46f is determined so that the restoration is not complete and some deformation remains. Therefore, due to the resulting elastic force, the protrusion 46
f biases the stepped portion 1e in the direction of the arrow, thereby biasing the optical member 1 against the peripheral surface 2a of the image sensor 2b with a predetermined elastic force. The other configurations are similar to those of the embodiment shown in FIG. In the present embodiment, due to the structure of forming the arm 46e and the protrusion 46f, the dust-proof and moisture-proof functions cannot be sufficiently exerted as they are. In contrast,
For example, by covering the skimmer of the elastic structure portions (46e, 46f) of the lens frame 46 with another member, desired dustproof and moistureproof functions can be exhibited.

Furthermore, as another example of the elastic means, a combination of a wave spring and a disc spring may be used in addition to those described above.

Although the present invention has been described above with reference to the embodiments, the present invention should not be construed as being limited to the above embodiments, and it goes without saying that appropriate modifications and improvements are possible. is there. For example, in the present embodiment, the image sensor 2b and the substrate PC are connected by the wire W, but the image sensor 2 is provided with wiring inside.
The signal may be taken out from the back surface (the side opposite to the photoelectric conversion unit) or the side surface of b. With such a configuration, it is possible to secure a wide peripheral surface of the image sensor and easily connect the wires. Further, in the present embodiment, the image pickup unit is composed of only the image pickup element which is a bare chip,
By attaching a protective member such as glass to the upper surface or the lower surface thereof, an integrated image pickup unit can be configured, and such an image pickup unit may be used. The substrate is not limited to a hard substrate, but may be a flexible substrate. Further, in the above description, a mode in which the leg portion of the optical member is brought into contact with the surface of the image pickup element facing the lens portion has been described as a preferred embodiment. Alternatively, the side surface of the image pickup element that intersects the surface may be in contact with the side surface of the image pickup element. Further, for example, the leg portion is not in contact with the image pickup element, but is in contact with the board of the image pickup apparatus. Even with such a configuration, the effect that the rattling of the lens and the damage due to the external force can be suppressed for a long period of time by the elastic force of the elastic means. Of course, the aspect in which the leg portion is brought into contact with the surface of the image pickup element facing the lens portion appropriately designs the length dimension of the leg portion brought into contact with the image pickup element so as to match the image point position of the lens. This is particularly preferable in that it is possible to obtain a highly reliable imaging device that can be assembled with high accuracy even without adjustment. The image pickup device of the present invention can be incorporated into various devices such as a mobile phone, a personal computer, a PDA, an AV device, a television, and a home electric appliance.

[0064]

According to the present invention, the number of parts can be reduced, the size can be reduced, and the rattling of the lens and the damage due to external force can be suppressed for a long period of time, while being inexpensive.
It is possible to provide an image pickup apparatus which can be assembled accurately without adjustment, has a dustproof and moistureproof structure, and has high reliability.

[Brief description of drawings]

FIG. 1 is a sectional view of an image pickup apparatus according to a first embodiment.

FIG. 2 is a perspective view of the image pickup apparatus in FIG.

FIG. 3 is a perspective view of an optical member.

FIG. 4 is a bottom view of an optical member.

FIG. 5 is a top view of the image sensor.

FIG. 6 is a cross-sectional view showing an example of a conventional imaging device.

FIG. 7 is a cross-sectional view of an image pickup apparatus including a modification of elastic means.

FIG. 8 is a perspective view showing an optical member and elastic means in a disassembled state.

FIG. 9 is a cross-sectional view of the image pickup apparatus according to the second embodiment.

FIG. 10 is a cross-sectional view of an image pickup apparatus including another modification of elastic means.

FIG. 11 is a cross-sectional view of an image pickup apparatus according to a third embodiment.

FIG. 12 is a perspective view of another modification of the elastic means.

FIG. 13 is a cross-sectional view of an imaging device including another modification of elastic means.

[Explanation of symbols]

1, 11, 19, 36 Optical member 1a, 1a 'lens part 1c leg 1d contact part 2 Imaging unit 2a Surrounding surface 2b image sensor 2d photoelectric converter 3 diaphragm 4,46 mirror frame 5,15 Light shield 6 Elastic means 7 filters 8 Light-shielding sheet 9 Subject side lens 9a lens part 16 Elastic member 1'Image side lens 5 ', 26 holding member 7'filter

Continued front page    (72) Inventor Yuichi Honda             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             Inside the company F-term (reference) 2H044 AA15 AB15 AD02 AD03 AG01                 5C022 AA12 AA13 AB12 AB13 AC42                       AC54 AC55 AC65 AC66 AC70

Claims (11)

[Claims] 1. A substrate, a photoelectric conversion unit, an image sensor mounted on the substrate, a lens unit for forming a subject image on the photoelectric conversion unit included in the image sensor, and the lens unit. An image pickup device, comprising: an optical member having a leg portion for supporting the optical member; and an elastic member, wherein the optical member is biased toward the image pickup element by the elastic force of the elastic member. apparatus. 2. The leg portion is brought into contact with the surface of the image pickup element facing the lens portion with a load of 5 g or more and 500 g or less due to the elastic force of the elastic means. The imaging device according to. 3. A cover member which is attached to a lens frame fixed to the substrate, is arranged closer to the subject than the lens portion, presses the elastic means, and at least a part of which has a cover member capable of transmitting light. The imaging device according to claim 1 or 2. 4. The image pickup apparatus according to claim 3, wherein the elastic means is configured separately from the optical member and the cover member. 5. The image pickup apparatus according to claim 1, wherein the elastic means is a coil spring. 6. The image pickup apparatus according to claim 1, wherein the elastic means is a sheet-shaped member having an opening at the center. 7. The image pickup apparatus according to claim 6, wherein the sheet-shaped member is made of a member having a light-shielding property, and also has a function of an aperture that defines an F number of the lens portion. 8. The image pickup apparatus according to claim 3, wherein the elastic means is integrated with the cover member. 9. The image pickup apparatus according to claim 3, wherein the elastic means is integrated with the optical member. 10. A substrate, a photoelectric conversion unit, an image sensor mounted on the substrate, a lens unit for forming a subject image on the photoelectric conversion unit included in the image sensor, and the lens unit. An optical member having a leg portion for supporting the optical member, and a lens frame having the elastic member while supporting the optical member, and the elastic member elastic force causes the optical member to move to the image sensor. An imaging device characterized by being biased toward. 11. The leg portion is brought into contact with the surface of the image pickup element facing the lens portion under a load of 5 g or more and 500 g or less due to the elastic force of the elastic means. The imaging device according to.