Patent Description:
For example, PTL <NUM> (<CIT>) discloses a solid-state image pickup device including a protruding portion on a wiring substrate. At a predetermined distance from an adhesion region between a holder and the wiring substrate, the protruding portion is formed along the adhesion region and adhesive for bonding the holder to the wiring substrate is applied to the protruding portion. PTL <NUM> (<CIT>) discloses an adhesion connector for components to be mutually adhered, in which an end-edge portion of one component abuts to and adheres, with adhesive, to the other component. Each side in the thickness direction of the leading end of the end-edge portion has a recess formed thereon. An abutting protrusion between the recesses adheres to the other component with the adhesive, and the recess on each side houses an excess of the adhesive.

The document <CIT> discloses an image pickup device according to the preamble of claim <NUM>.

PTL <NUM> or PTL <NUM> discloses the configuration of an image pickup camera in which a holder holding a lens and a wiring substrate on which an image pickup element is mounted are secured with adhesive. However, for the configuration of the image pickup camera described in PTL <NUM> or PTL <NUM>, there is a risk that occurrence of flowing or separating of securing material, such as the adhesive, during manufacturing may cause soiling of the image pickup element, a crack, or a reduction in adhesion strength.

The present invention has been made in consideration of the problem, and an object of the present invention is to provide an image pickup camera and a multi-eye image pickup device that can inhibit the flowing of securing material from occurring during manufacturing.

The object, another object, and novel features of the present invention will be clarified with the descriptions herein and the accompanying drawings.

The invention proposes to solve the above problem by providing an image pickup camera according to claim <NUM>.

According to the embodiment described above, flowing of securing material can be inhibited from occurring during manufacturing.

Each embodiment will be described, as necessary for convenience, with division into a plurality of sections or a plurality of embodiments. Unless otherwise specified, those are related to each other. For example, one is related to a modification, detail, or supplementary explanation of the entirety or part of another. In a case where referring to the number of elements (including number of pieces, numerical value, quantity, and range are included) in each embodiment, unless otherwise specified or obviously theoretically limited to a specific number, the number of elements is not limited to the specific number, and thus may be not less than or not more than the specific number.

Furthermore, needless to say, the constituent elements of each embodiment (including elemental steps) are not necessarily essential unless otherwise specified or obviously theoretically considered to be essential. Similarly, when referring to the shape and positional relationship of each constituent element in each embodiment, unless otherwise specified or obviously theoretically contradicted, a shape substantially approximate to or similar to the shape thereof is included. This is applicable to the numerical value and the range, similarly.

The embodiments of the present invention will be described in detail below on the basis of the drawings. Note that the same members are denoted with the same reference signs, in principle, in all figures for describing the embodiments, and the descriptions thereof will not be repeated.

<FIG> is a perspective view of an exemplary schematic configuration of an image pickup camera according to a first embodiment of the present invention, and <FIG> is a plan view of an exemplary structure of a holding member in <FIG>. <FIG> is a plan view of an exemplary outer shape of the image pickup camera of <FIG> that has been assembled, and <FIG> is a sectional view of an exemplary structure taken along line A-A' of <FIG>.

The image pickup camera <NUM> illustrated in <FIG> includes an optical lens <NUM>, the holding member <NUM>, a substrate <NUM>, an image pickup element <NUM>, and securing material <NUM>. The optical lens <NUM> is held and secured by the holding member <NUM>, resulting in integration with the holding member <NUM>. The substrate <NUM> has the image pickup element <NUM> mounted thereon, and the securing material <NUM> for securing the substrate <NUM> and the holding member <NUM> is applied on the periphery of the image pickup element <NUM> on the substrate <NUM>. A representative example of the image pickup element <NUM> is a CMOS image sensor or a CCD image sensor.

As illustrated in <FIG>, the holding member <NUM> has a bottom portion (coupling face) <NUM> that is a looped face opposed to the substrate <NUM> and that is secured to the substrate <NUM> through the securing material <NUM>. One section in the loop direction of the bottom portion <NUM> includes a corner portion <NUM>. Here, the holding member <NUM> has a recess <NUM> open toward the image pickup element <NUM>, at the corner portion <NUM>. In this example, the bottom portion <NUM> includes four corner portions <NUM>, and each of the four corner portions <NUM> is provided with the recess <NUM>.

As illustrated in <FIG>, and <FIG>, with the bottom portion (coupling face) <NUM> of the holding member <NUM> abutting on the securing material <NUM>, the holding member <NUM> is secured to the substrate <NUM>, through the securing material <NUM> in a state of surrounding the periphery of the image pickup element <NUM>. At this time, the holding member <NUM> and the substrate <NUM> are secured such that the optical axis <NUM> of the optical lens <NUM> integrated with the holding member <NUM> is substantially perpendicular to the image pickup face of the image pickup element <NUM> and the focus of the optical lens <NUM> substantially agrees with the image pickup element <NUM>.

During manufacturing, the securing material <NUM> in melt is applied to the substrate <NUM>, and solidifies at a securing position determined between the holding member <NUM> and the substrate <NUM>, resulting in securing of the holding member <NUM> and the substrate <NUM>. It is considered that specific examples of the securing material <NUM> include any material that varies from melt to solidification, such as adhesive, resin, and solder.

This arrangement enables the optical lens <NUM> to form visual information (subject image) acquired from outside, on the image pickup element <NUM>, so that the image pickup camera <NUM> acquires an outside image.

<FIG> is a perspective view of exemplary shapes of the recess and the securing material in the image pickup camera of <FIG>, and <FIG> is an enlarged plan view of a part of <FIG>. <FIG> illustrate a first comparative example of <FIG>, respectively. <FIG> are sectional views for describing a mechanism for acquiring the shape of <FIG>.

For the image pickup camera <NUM>, generally, it is ideal that the optical lens <NUM> and the image pickup element <NUM> has a positional relationship where the optical axis <NUM> of the optical lens <NUM> is perpendicular to the image pickup face of the image pickup element <NUM> and the focal position of the optical lens <NUM> agrees with the image pickup face of the image pickup element <NUM>. In order to achieve such a positional relationship, the manufacturing process of the image pickup camera <NUM> includes a process of adjusting the positional relationship between the optical lens <NUM> and the image pickup element <NUM> and a process of solidifying the securing material <NUM> in melt at an adjusted position. As a result, desired optical performance is acquired.

However, as illustrated in <FIG>, if a holding member <NUM>' with an optical lens, abutting on securing material <NUM> has no recess <NUM> at a corner portion <NUM>, in some cases, the securing material <NUM> in melt accumulates at the corner portion of the holding member <NUM>' due to surface tension. This phenomenon results from capillary action, and an inner wall located at the corner portion of the holding member <NUM>' functions as a thin tube.

Such a state causes, as illustrated in <FIG>, the securing material <NUM> that has accumulated at the corner portion, to flow and spread, resulting in adhesion of the securing material <NUM> to an image pickup element <NUM>. There is a risk that the securing material <NUM> adhering thereto may cause soil of the image pickup element <NUM> or a crack due to thermal stress. Furthermore, the accumulation of the securing material <NUM> at the corner portion causes, in some cases, a reduction in the applied amount of the securing material <NUM> at side portions excluding the corner portion of the holding member <NUM>'. As a result, there is a risk that occurrence of thinning or separating of the securing material <NUM> at the side portions of the holding member <NUM>' may cause a reduction in securing strength.

Thus, as illustrated in <FIG>, the holding member <NUM> in the image pickup camera <NUM> according to the first embodiment has the recess <NUM> open toward the image pickup element <NUM>, at the corner portion. Such a structure causes a shape in which the securing material <NUM> at the corner portion is stored inside the recess <NUM>, so that the securing material <NUM> is inhibited from accumulating not more than the capacity of the recess <NUM> at the corner portion.

As a result, as illustrated in <FIG>, the securing material <NUM> is inhibited from flowing and spreading toward the image pickup element <NUM>, so that the securing material <NUM> can be prevented from adhering to the image pickup element <NUM>. Furthermore, the securing material <NUM> cannot accumulate at the corner portion greatly over the capacity of the recess <NUM>. Thus, the securing material <NUM> is inhibited from reducing at the side portions, so that the securing material <NUM> can be prevented from thinning or separating.

A mechanism of storing the securing material <NUM> at the corner portion inside the recess <NUM> can be described on the basis of the wetting and spreading behavior of the securing material <NUM> at the holding member <NUM>. As illustrated in <FIG>, pressing the bottom portion (coupling face) <NUM> of the holding member <NUM> against the securing material <NUM>, causes the recess <NUM> to suck the securing material <NUM> due to capillary action. As illustrated in <FIG>, the wetting shape of the securing material <NUM> is temporarily formed.

As illustrated in <FIG>, in a state where the securing material <NUM> adheres to the upper wall W1 of the recess <NUM>, the securing material <NUM> spreads wetly while generally keeping a wetting contact angle determined by the balance between the surface tension of the securing material <NUM>, the surface tension of the holding member <NUM>, and the interfacial tension between the securing material <NUM> and the holding member <NUM>. However, for wetting spread of the securing material <NUM> over the edge EG1 of the upper wall W1, as illustrated in <FIG>, the securing material <NUM> needs to spread wetly through the shape of the securing material <NUM> having a contact angle larger than that in the state of <FIG>.

For the wetting spread through such a shape of the securing material <NUM>, a large supply of securing material <NUM> and driving force for strong wetting spread are required in comparison to the state of <FIG>. Thus, the securing material <NUM> that has risen wetly at the corner portion due to the capillary action cannot get over the edge EG1 of the recess <NUM> formed at the corner portion. This mechanism causes the recess <NUM> to suck the securing material <NUM>, resulting in further storage of the securing material <NUM> inside the recess <NUM>.

Note that, in <FIG>, preferably, the size h2 in the height direction of the recess <NUM> is larger than the size h1 in the height direction of the securing material <NUM> that has been applied on the substrate <NUM>. This is because, if the size h2 of the recess <NUM> is smaller than the size h1 of the securing material <NUM>, there is a risk that the securing material <NUM> is likely to get over the edge EG1 at the instant when the holding member <NUM> is pressed against the securing material <NUM> as in <FIG>.

<FIG> is a perspective view of an exemplary detailed structure of the holding member of <FIG>, and <FIG> is a perspective view of a second comparative example of <FIG>. As described above, with the holding member <NUM> secured to the substrate <NUM>, the recess <NUM> forms a space closed by a wall except for the side on which the image pickup element <NUM> is mounted. Specifically, as illustrated in <FIG>, the recess <NUM> has the upper wall W1, side walls W2a and W2b, and a rear wall W3. The upper wall W1 is a wall intersecting with the perpendicular direction (Z-axis direction) of a face of the substrate <NUM>. Each of the side walls W2a and W2b is a wall intersecting with the loop direction R of the bottom portion (coupling face) <NUM>. The rear wall W3 is a wall intersecting with the direction from the inner circumferential side to the outer circumferential side of the bottom portion <NUM>.

In <FIG>, the wetting of the securing material is deterred from getting over the edge EG1 of the upper wall W1 as described in <FIG>. Furthermore, because of a similar reason, the wetting of the securing material is deterred from getting over the edge EG2 of each of the side walls W2a and W2b. The two deterrents store the securing material inside the recess <NUM>.

As a result, as described above, flowing of the securing material <NUM> toward the image pickup element <NUM> can be inhibited from occurring during manufacturing. Furthermore, the securing material <NUM> is inhibited from reducing at the side portions, in accordance with the capacity of the recess <NUM>, so that the securing material <NUM> can be prevented from thinning or separating. Prevention of the securing material <NUM> from thinning or separating, enables constant retention of the positional relationship between the holding member <NUM> (furthermore, the optical lens <NUM>) and the substrate <NUM>, and enables sufficient retention of the coupling strength between the holding member <NUM> and the substrate <NUM>.

Meanwhile, <FIG> illustrates a holding member <NUM>" having a recess, which is not limited to a corner portion, over the entire inner circumference of a bottom portion, differently from the structure of <FIG>. In this case, securing material spreads wetly in the recess from the corner portion as the starting point, similarly to the case of <FIG>. On this occasion, the edge EG1" of an upper wall W1" deters the wetting spread of the securing material, differently from the case of <FIG>.

However, the deterrent due to the edge EG2 of each side wall in the structure of <FIG> does not work in the structure of <FIG>. Thus, the deterrent to the wetting spread of the securing material is insufficient, so that the securing material may not be sufficiently inhibited from flowing and spreading toward an image pickup element. Because no side walls W2a and W2b are provided, the accumulation amount of the securing material to the corner portion is difficult to control. Thus, there is a risk that the securing material <NUM> may become thin or separate at side portions. Thus, use of the structure as in <FIG> is advantageous.

Note that, in a case where the securing material solidifies in the recess <NUM> of <FIG>, the side walls W2a and W2b each can catch, as tensile force, force in the perpendicular direction of the wall, as illustrated in <FIG>. As a result, the use of the structure of <FIG> allows, in some cases, further improvement of the coupling strength between the holding member <NUM> and the substrate <NUM> (particularly, shear strength) in comparison to the structure of <FIG> or the structure of <FIG>.

<FIG> is a perspective view of an exemplary structure of the vicinity of a holding member in an image pickup camera according to a second embodiment of the present invention, and <FIG> is an enlarged plan view of a part of <FIG>. The image pickup camera according to the second embodiment is different from the image pickup camera according to the first embodiment in terms of the shape of a recess <NUM> of the holding member <NUM>. In <FIG>, the recess <NUM> provided at a corner portion <NUM> forms a tunnel-like space penetrating between the inner circumference and the outer circumference of a looped bottom portion (coupling face) <NUM>, with the holding member <NUM> secured to a substrate <NUM>.

Use of the image pickup camera according to the second embodiment enables acquisition of a similar effect to that according to the first embodiment, and additionally causes securing material <NUM> to have more difficulty in accumulating on the image pickup element <NUM> side of the corner portion <NUM> in comparison to the case according to the first embodiment. Thus, in some cases, the securing material <NUM> can be further inhibited from flowing and spreading toward the image pickup element <NUM>. Note that, for example, depending on the quality of the securing material <NUM>, external light possibly leaks toward the image pickup element <NUM> through the recess <NUM>. Thus, from this point, the structure according to the first embodiment is preferable.

<FIG> is a perspective view of an exemplary structure of the vicinity of a holding member in an image pickup camera according to a third embodiment of the present invention, and <FIG> is an enlarged plan view of a part of <FIG>. The image pickup camera according to the third embodiment is different from the image pickup camera according to the first embodiment in that, as illustrated in <FIG>, a plurality of recesses 124a, 124b, and 124c (here, three recesses) is provided at a corner portion <NUM> of the holding member <NUM>.

For example, a recess <NUM> provided at the corner portion as illustrated in <FIG>, functions as a capillary that sucks the securing material <NUM>, and serves to confine the securing material <NUM> sucked, inside the recess <NUM>. The capacity of the recess <NUM> is determined in consideration of, for example, how much of the total amount of the securing material <NUM> should be distributed to the side portions. Here, if the recess <NUM> requires increasing in capacity, for example, the interval between the side walls W2a and W2b illustrated in <FIG> requires widening.

In this case, the recess <NUM> functions as a thick capillary. Thus, there is a risk that the suction force for the securing material <NUM> may be weakened, and additionally the confining force for the securing material <NUM> sucked inside the recess <NUM> may also be weakened. Thus, as in <FIG>, the provision of the plurality of recesses 124a, 124b, and 124c at the one corner portion <NUM> is advantageous. In this case, each of the recesses 124a, 124b, and 124c functioning as a thin capillary strongly sucks securing material <NUM>, and additionally can confine the securing material <NUM> sucked inside the recess due to strong force.

Use of the image pickup camera according to the third embodiment enables acquisition of a similar effect to that according to the first embodiment, and additionally causes the plurality of recesses to actively to suck the securing material <NUM> due to capillary action and store the securing material <NUM> inside, in comparison to the case according to the first embodiment. Thus, the securing material <NUM> can be further inhibited from flowing and spreading toward an image pickup element <NUM>. Even a case where the entire capacity of the recesses requires increasing to some extent can be handled, resulting in further improvement of the degree of freedom in determination of the capacity of the recesses.

<FIG> are respectively sectional views of an exemplary structure of the vicinity of a holding member in an image pickup camera according to a fourth embodiment of the present invention. The image pickup camera according to the fourth embodiment is different from the image pickup camera according to the first embodiment in terms of the shape of a recess <NUM> of the holding member <NUM>. <FIG> illustrate that the recess <NUM> is further provided with a second recess <NUM>. The recess <NUM> and the second recess <NUM> form a stepwise stage when viewed on a plane (XZ plane) in the perpendicular direction of a face of a substrate <NUM>.

Use of the image pickup camera according to the fourth embodiment enables acquisition of a similar effect to that according to the first embodiment, and additionally enables further reliable storage of securing material <NUM> inside the recess <NUM> in comparison to the case according to the first embodiment. Specifically, as described in <FIG>, for example, in a case where the size h1 in the height direction of the securing material <NUM> is larger than the size h2 in the height direction of the recess <NUM> due to a factor of some kind, there is a risk that the securing material <NUM> may get over the edge EG1. Meanwhile, in <FIG> (similarly, in <FIG>), the provision of the second recess <NUM> causes stepwise disposition of upper walls W11 and W12 and edges EG11 and EG12. Thus, even if the securing material <NUM> gets over the edge EG11, the edge EG12 can deter the wetting of the securing material.

<FIG> is a perspective view of an exemplary schematic configuration of a multi-eye image pickup device according to a fifth embodiment of the present invention. The multi-eye image pickup device <NUM> illustrated in <FIG> includes an image pickup camera <NUM>, a second image pickup camera <NUM>, and a casing <NUM>. The second image pickup camera <NUM> has a structure equivalent to that of the image pickup camera <NUM>. The casing <NUM> secures the image pickup camera <NUM> and the second image pickup camera <NUM> at positions separated by a predetermined distance such that the respective optical axes <NUM> of the image pickup camera <NUM> and the second image pickup camera <NUM> are substantially parallel.

The multi-eye image pickup device <NUM> detects identical points between respective images acquired by the image pickup camera <NUM> and the second image pickup camera <NUM> and combines both of the images, to generate a range image including outside three-dimensional information. Thus, when the multi-eye image pickup device <NUM> acquires outside range information, the respective optical characteristics of the image pickup cameras include in the multi-eye image pickup device <NUM> are preferably identical.

An example of the optical characteristic of each image pickup camera related to the acquisition of the range information is the response characteristic of a focal position to temperature (hereinafter, referred to as a defocus temperature characteristic). For example, in a case where there is a large difference between the respective defocus temperature characteristics of the image pickup cameras included in the multi-eye image pickup device <NUM>, a variation occurs in resolution between respective images acquired by the image pickup cameras when the outside temperature varies. Such a state causes the multi-eye image pickup device <NUM> to have difficulty in detecting identical points between the respective images acquired by the image pickup cameras, resulting in deterioration in accuracy of calculating a range in a generated range image.

The optical characteristic, such as the defocus temperature characteristic, depends on the structure or configuration of an optical lens, a holding member, securing material, an image pickup element, and a substrate included in the image pickup camera. In particular, as described above, the securing material applied in melt during manufacturing accumulates at a corner portion of the holding member and causes a variation in shape. Thus, the securing material is a main factor for a variation in optical characteristic. Thus, application of any of the configurations described in the first to fourth embodiments to each of the image pickup camera <NUM> and the second image pickup camera <NUM> is advantageous.

<FIG> is a sectional view of an exemplary schematic structure of the multi-eye image pickup device of <FIG>, and <FIG> is a sectional view of a comparative example of <FIG>. According to the comparative example of <FIG>, each of an image pickup camera <NUM>' and a second image pickup camera <NUM>' includes the holding member <NUM>' illustrated in <FIG>. In this case, as illustrated in <FIG>, the respective optical axes <NUM> of the image pickup camera <NUM>' and the second image pickup camera <NUM>' are not parallel, resulting in an event in which the positional relationship between an optical lens <NUM> and an image pickup element <NUM> of the image pickup camera <NUM>' is different from the positional relationship between an optical lens <NUM> and an image pickup element <NUM> of the second image pickup camera <NUM>'. As a result, only the image pickup element <NUM> in one of the two image pickup cameras is available for focusing, and it may be difficult to detect identical points between respective images acquired by the image pickup cameras.

The example of <FIG> indicates the image pickup camera <NUM>' having a difference in the accumulation amount of securing material <NUM> between two corner portions due to occurrence of misalignment during pressing the holding member <NUM>' against the securing material <NUM>. The difference causes, in some cases, for example, that the amount of the securing material <NUM> at side portions of the holding member <NUM>' is different every side portion. Thus, there is a risk that the optical axis <NUM> may incline. Furthermore, the difference in the accumulation amount of securing material <NUM> between the two corner portions causes, in some cases, adhesion force at the two corner portions to vary along with outside temperature. As a result, even if the optical axis <NUM> has no inclination during manufacturing, the optical axis <NUM> may incline along with a variation in outside temperature.

Meanwhile, use of the multi-eye image pickup device according to the fifth embodiment, enables, as described in each embodiment, substantially constant retention of the accumulation amount of securing material <NUM> at each corner portion, in accordance with the capacity of a recess <NUM>. This arrangement enables substantially constant retention of the amount of the securing material <NUM> at side portions of each holding member <NUM>, at each side portion, and enables substantially constant retention of adhesion force at each corner portion regardless of outside temperature. As a result, as illustrated in <FIG>, the optical axes <NUM> of the image pickup camera <NUM> and the second image pickup camera <NUM> can be retained in parallel, so that identical points between respective images acquired by the image pickup cameras can be detected easily.

The use of the multi-eye image pickup device according to the fifth embodiment enables acquisition of a similar effect to those according to the first to fourth embodiments, and additionally enables inhibition of a variation in the shape of the securing material in each image pickup camera. Thus, the range calculating accuracy of the multi-eye image pickup device can be prevented from deteriorating due to a factor, such as a variation in temperature.

The present invention made by the present inventors has been specifically described above on the basis of the embodiments.

Claim 1:
An image pickup camera comprising:
a substrate (<NUM>) on which an image pickup element (<NUM>) is mounted;
an optical lens (<NUM>) configured to form a subject image on the image pickup element (<NUM>);
a holding member (<NUM>) holding the optical lens and surrounding a periphery of the image pickup element; and
securing material (<NUM>) securing the substrate and the holding member (<NUM>),
wherein the holding member (<NUM>) has a coupling face (<NUM>) that is a quadrangular or substantially circular ring-shaped face opposed to the substrate (<NUM>), the coupling face (<NUM>) being secured to the substrate through the securing material (<NUM>),
one section in a peripheral direction of the coupling face (<NUM>) includes a corner portion (<NUM>),
the holding member (<NUM>) has at least one recess (<NUM>) open toward a side of the substrate (<NUM>) and toward a side of the image pickup element (<NUM>),
the recess (<NUM>) has an upper wall (W1), positioned so as to face and to be spaced apart from an upper surface of the substrate (<NUM>),
wherein the recess (<NUM>) is formed at the corner portion (<NUM>),
wherein, with the holding member (<NUM>) secured to the substrate (<NUM>), the recess (<NUM>) and the substrate (<NUM>) form a space closed by a wall except for the side of the image pickup element,
wherein the coupling face (<NUM>) has a plurality of the corner portions (<NUM>),
characterized in that one recess (<NUM>) is provided at each of the plurality of the corner portions (<NUM>) and has side walls (W2a, W2b) perpendicular to the peripheral direction of the coupling face (<NUM>), wherein the side walls (W2a, W2b) and the upper wall (W1) include right-angled edges (EG1, EG2) deterring the wetting of the securing material (<NUM>) from getting over the edge (EG1, EG2) of each of the side walls (W2a, W2b) and the top wall (W1).