JP2009060380A - Camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module protecting an inner space from dust while maintaining communication between the inner space opposed to an image sensor and an outer space and avoiding cost increase. <P>SOLUTION: The camera module includes the image sensor 2 mounted on a substrate 1, a cylindrical case 3 installed above the substrate 1 to cover the image sensor 2, an infrared ray removing filter 4 housed in the cylindrical case 3 and having one surface opposed to the image sensor 2 and a lens 5 housed in the cylindrical case 3 and opposed to the other surface of the infrared ray removing filter 4. The inner space S1 between the image sensor 2 and the infrared ray removing filter 4 communicates with the outer space through a vent 3a. Within a pedestal 31 of the cylindrical case 3, an inner cylinder wall part 33 having many minute recessed grooves formed in its bottom 33a and surrounded by an outer wall part 32 is protrudingly formed and the bottom 33a is brought into abutment on an peripheral edge of the image sensor 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a camera module in which a lens housed in a cylindrical case is opposed to an image sensor directly or via an infrared filter, and in particular, dew condensation is caused by communicating an internal space near the image sensor with an external space. The present invention relates to a camera module that prevents the above.

  A camera module incorporated in a small electronic device such as a cellular phone includes a lens housed in a lens barrel (lens holder) of a cylindrical case and light mounted on the substrate and collected by the lens as an electrical signal. In many cases, an infrared sensor is disposed between the lens and the image sensor. Generally, in this type of camera module, a hollow cylindrical case is mounted on a substrate so as to cover the imaging element, and a lens housed in the cylindrical case is directly connected to the imaging element via an infrared filter. It comes to oppose. The cylindrical case has at least a lens barrel portion that accommodates a lens, but has a pedestal portion that is fixed to the substrate separately from the lens barrel portion and connects the lens barrel portion on the pedestal portion. Thus, a camera module that forms a cylindrical case is widely known. However, an integrally molded cylindrical case is also known.

  In the camera module schematically configured in this way, when the internal space facing the image sensor in the cylindrical case is sealed, water vapor contained in the internal space is condensed on the image sensor due to a change in environmental temperature, Condensation may occur on one surface of the infrared ray removal filter facing the image sensor, and in this case, the performance of the camera module is significantly deteriorated. Further, when the internal space is sealed, there is a risk that the image sensor is damaged by the pressure of thermally expanded air. Therefore, conventionally, a structure in which the internal space facing the image sensor in the cylindrical case is communicated with the external space through a vent or the like provided at an appropriate location has been studied. In this case, since there is an increased risk of dust contained in the outside air entering the internal space and adhering to the image sensor, a new measure for protecting the image sensor from dust is desired.

As a camera module that can prevent the intrusion of dust into the internal space while communicating the internal space facing the image sensor with the external space, the inner wall surface of the cylindrical case (lens holder) and the outside of the lens have been conventionally used. There is known a configuration in which a gap defined between a wall surface is communicated with the internal space and an air filter is fitted into the gap (for example, see Patent Document 1). In such a conventional camera module, since the outside air cannot reach the image sensor unless it passes through the gap in which the air filter is fitted, the image sensor is removed by removing dust contained in the outside air with this air filter. It is possible to protect from dust.
JP 2004-304605 A

  However, when a configuration using an air filter as in the conventional camera module disclosed in Patent Document 1, not only the number of parts is increased by the air filter, but also the assembly work becomes complicated, so the cost must be increased. There was a problem of being.

  The present invention has been made in view of the actual situation of such a conventional technique, and an object of the present invention is to provide a camera module that can protect the dust from the internal space facing the image pickup device and protect the dust from the external space, thereby avoiding an increase in cost. It is to provide.

  In order to achieve the above object, the present invention provides an image pickup device mounted on a substrate, an infrared removal filter whose one surface faces the image pickup device, a lens facing the other surface of the infrared removal filter, and these infrared rays. A hollow cylindrical case mounted on the substrate so as to house the removal filter and the lens so as to cover the imaging element, and an internal space existing between the imaging element and the infrared removal filter is outward In the camera module communicated with the exposed vent, the outer surface of the cylindrical case having a large number of minute concave grooves on the bottom surface at a location facing the peripheral edge of the imaging element inside the cylindrical case An inner cylindrical wall portion surrounded by a portion is projected, and the inner space is surrounded by the inner cylindrical wall portion by bringing the bottom surface of the inner cylindrical wall portion into contact with the peripheral edge portion of the imaging element. None and before The interior space through the groove group is configured to be communicated with the vent.

  In the camera module configured as described above, the internal space existing between the imaging element and the infrared filter is communicated with the external space via the groove group on the bottom surface of the inner cylindrical wall portion of the cylindrical case. The inner space can be protected from dust by forming a concave groove on the bottom surface of the inner cylinder wall portion so that condensation is unlikely to occur in the inner space and dust contained in the outside air cannot pass through. . Further, since the inner cylindrical wall portion can be integrally formed inside the cylindrical case, the number of parts does not increase and the assembling work is not complicated. In addition, since the cylindrical case is mounted on the substrate in a posture in which the inner cylindrical wall portion is placed on the image sensor, the distance between the image sensor and the lens, which requires high optical accuracy, is set to the dimension of the cylindrical case. Therefore, it is possible to omit complicated adjustment work.

  In the above-described configuration, the cylindrical case holds the infrared filter on the top surface portion and is fixed on the substrate so as to cover the imaging device, and the lens barrel that houses the lens and is mounted on the pedestal portion It is preferable that the inner cylindrical wall portion is formed on the pedestal portion because the pedestal portion can be easily molded with a mold even if the inner cylindrical wall portion is attached.

  In order to achieve the above object, the present invention provides an image pickup device mounted on a substrate, a lens facing the image pickup device with a predetermined interval, and housing the lens to store the image pickup device. In a camera module comprising a hollow cylindrical case mounted on the substrate so as to cover, an internal space existing between the imaging element and the lens is communicated with a vent hole exposed to the outside, An inner cylindrical wall portion that has a large number of minute concave grooves on the bottom surface and is surrounded by the outer wall portion of the cylindrical case is provided at a location facing the peripheral edge portion of the imaging element inside the cylindrical case. The inner space is surrounded by the inner cylindrical wall portion by bringing the bottom surface of the inner cylindrical wall portion into contact with the peripheral edge portion of the imaging element, and the inner space is interposed through the groove group. Is configured to communicate with the vent.

  The camera module configured in this way has an internal space between the imaging element and the lens that communicates with the external space via a groove group on the bottom surface of the inner cylindrical wall portion of the cylindrical case. It is possible to protect the internal space from dust by forming a concave groove on the bottom surface of the inner cylinder wall portion so that condensation does not easily occur in the space and dust contained in the outside air cannot pass through. Further, since the inner cylindrical wall portion can be integrally formed inside the cylindrical case, the number of parts does not increase and the assembling work is not complicated. In addition, since the cylindrical case is mounted on the substrate in a posture in which the inner cylindrical wall portion is placed on the image sensor, the distance between the image sensor and the lens, which requires high optical accuracy, is set to the dimension of the cylindrical case. Therefore, it is possible to omit complicated adjustment work.

  In the above configuration, the cylindrical case can be easily molded with a mold even if the inner cylindrical wall portion is attached. Therefore, if the cylindrical case is an integrally molded product, the distance between the imaging element and the lens is higher. And the assembly workability is improved.

  In addition, the ditch | groove of the bottom face of an inner cylinder wall part can be formed by hairline processing, for example. The groove depth of the concave groove is preferably 1 to 2 microns.

  In addition, a vent for communicating the internal space in the vicinity of the image sensor with the external space can be provided at an appropriate place, but a notch groove-like vent is formed on the bottom surface of the outer wall portion of the cylindrical case, If this vent hole is positioned on the substrate, the vent hole can be projected in the space around the inner cylinder wall portion, so that it becomes easy to function the minute groove group of the inner cylinder wall portion as a communication path. .

  According to the camera module of the first aspect of the present invention, the internal space existing between the imaging device and the infrared filter is separated from the external space via the groove group on the bottom surface of the inner cylindrical wall portion of the cylindrical case. Since they are communicated with each other, the internal space can be protected from dust by forming a minute groove so that dew does not easily form in the internal space and dust contained in the outside air cannot pass therethrough. Further, even if the inner cylindrical wall portion is provided in the cylindrical case, the number of parts is not increased and the assembly work is not complicated, so that an increase in cost can be avoided. In addition, since the cylindrical case is mounted on the substrate in a posture in which the inner cylindrical wall portion is placed on the image sensor, complicated adjustment work is performed by defining the distance between the image sensor and the lens only by the dimensions of the cylindrical case. Can be omitted.

  According to the camera module of the third aspect of the present invention, the internal space existing between the imaging element and the lens is communicated with the external space via the groove group on the bottom surface of the inner cylindrical wall portion of the cylindrical case. Therefore, it is possible to protect the internal space from dust by forming a minute groove so that condensation does not easily occur in the internal space and dust contained in the outside air cannot pass through. Further, even if the inner cylindrical wall portion is provided in the cylindrical case, the number of parts is not increased and the assembly work is not complicated, so that an increase in cost can be avoided. In addition, since the cylindrical case is mounted on the substrate in a posture in which the inner cylindrical wall portion is placed on the image sensor, complicated adjustment work is performed by defining the distance between the image sensor and the lens only by the dimensions of the cylindrical case. Can be omitted.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a camera module according to a first embodiment of the present invention, and FIG. 2 is a pedestal of a cylindrical case used in the first embodiment. It is a principal part perspective view which shows the bottom part shape of a part.

  The camera module shown in FIG. 1 is mounted on the substrate 1 so as to cover the image pickup device 2 by connecting the image pickup device 2 such as an image sensor mounted on the substrate 1 to the lens barrel portion 30 and the pedestal portion 31. The hollow cylindrical case 3, the infrared removal filter 4 that is housed inside the cylindrical case 3 and whose lower surface in the figure faces the image sensor 2, and the upper surface in the figure of the infrared removal filter 4 that is housed in the lens barrel 30. And the lens 5 facing each other. The pedestal portion 31 of the cylindrical case 3 of the camera module is provided with an inner cylindrical wall portion 33 that is surrounded by the outer wall portion 32 and has a large number of fine grooves on the bottom surface 33a. Is in contact with the peripheral edge of the image sensor 2, and surrounds the internal space S <b> 1 existing between the image sensor 2 and the infrared filter 4.

  The imaging element 2 is formed by integrating a large number of photoelectric conversion elements on a plane, and outputs light that has been focused on the lens 6 and passed through the infrared filter 4 as image data (electrical signal). The image sensor 2 is fixed on the substrate 1 with the peripheral edge of the substrate 1 exposed, and the image sensor 2 and the substrate 1 are electrically connected by a technique such as wire bonding.

  The cylindrical case 3 is a molded product made of a synthetic resin material, and is configured by connecting a cylindrical lens barrel 30 to a rectangular box-shaped pedestal 31. The lower end (upper end in FIG. 2) of the pedestal 31 is an open end defined by a rectangular frame-shaped outer wall 32, and the bottom surface of the outer wall 32 is bonded and fixed to the peripheral edge of the substrate 1. ing. However, a part of the bottom surface of the outer wall portion 32 is formed with a notched groove-like vent 3a that is exposed to the outside and is not coated with an adhesive. Further, a concave step portion 3c in which the peripheral portion of the infrared ray removing filter 4 is disposed is formed on the top surface portion of the pedestal portion 31 in FIG. 1, and an outer wall is formed from the concave step portion 3c toward the open end. A rectangular frame-shaped inner cylinder wall portion 33 having a smaller diameter than the portion 32 is projected. The bottom surface 33a of the inner cylindrical wall portion 33 is formed with a number of fine concave grooves having a groove depth of 1 to 2 microns by a known hairline process, and this bottom surface 33a extends over the entire circumference of the inner cylindrical wall portion 33. In contact with the peripheral edge of the image sensor 2. On the other hand, a terrace-shaped opening 3b that functions as a diaphragm is formed at the center of the upper end of the lens barrel 30 in FIG. Even if the inner cylindrical wall portion 33 is attached to the pedestal portion 31 of the cylindrical case 3, the pedestal portion 31 can be easily molded using a mold.

  The outer peripheral surface of the lens 5 is bonded and fixed to the inner peripheral surface of the lens barrel 30. The lens 5 faces the image sensor 2 via the infrared ray removing filter 4 and comes into contact with the ceiling surface of the cylindrical case 3 so as to protrude from the opening 3b. The lens 5 is actually a combination of a plurality of lenses, but is illustrated as a single lens having a simplified shape in order to avoid the complexity of the drawing.

  The infrared removing filter 4 is a plate filter for blocking infrared rays collected by the lens 5. Since the peripheral edge portion of the infrared removal filter 4 is fitted and fixed to the concave step portion 3c of the top surface portion of the pedestal portion 31, the internal space S1 facing the image sensor 2 in the pedestal portion 31 is an infrared removal filter. The lid is closed by 4. Further, the inner space S1 is surrounded by the inner wall surface of the pedestal portion 31 including the inner cylindrical wall portion 33 over the entire circumference, but a minute groove group is formed on the bottom surface 33a of the inner cylindrical wall portion 33. Therefore, the internal space S1 is communicated with the vent 3a through the concave groove group.

  As described above, in the camera module according to the present embodiment, the inner cylindrical wall portion in which the internal space S <b> 1 existing between the imaging device 2 and the infrared filter 4 is attached to the pedestal portion 31 of the cylindrical case 3. Since the inner space S1 communicates with the external space through the concave groove group on the bottom surface 33a of the inner wall 33, the inner cylindrical wall portion is formed with a fine concave groove so that the internal space S1 is unlikely to form condensation and dust contained in the outside air cannot pass through By forming it on the bottom surface 33a of 33, the internal space S1 can be protected from dust. Further, even if the inner cylindrical wall portion 33 is installed in the pedestal portion 31, there is no increase in the number of parts and the complexity of the assembly work, so that an increase in cost can be avoided. Moreover, since the cylindrical case 3 is mounted on the substrate 1 in a posture in which the inner cylindrical wall portion 33 is placed on the image pickup device 2, the distance between the image pickup device 2 and the lens 5 that is required to have high optical accuracy. Can be defined only by the dimensions of the cylindrical case 3, and complicated adjustment work can be omitted.

  In this embodiment, the vent 3a formed on the bottom surface of the outer wall portion 32 of the pedestal portion 31 protrudes into the space around the inner cylindrical wall portion 33. The groove group is easy to function as a communication path. However, a vent for communicating the internal space S1 with the external space may be provided at another location.

  FIG. 3 is a cross-sectional view of the camera module according to the second embodiment of the present invention, and the same reference numerals are given to portions corresponding to those in FIG.

  The camera module shown in FIG. 3 does not include a plate-shaped infrared ray removing filter, and the cylindrical case 3 in which the inner cylindrical wall portion 33 is provided is an integrally molded product as described above. This is very different from the embodiment. That is, in the second embodiment, the internal shape of the cylindrical case 3 can be simplified because the lens 5 only needs to be directly opposed to the image pickup device 2, and thus the inner portion placed on the peripheral portion of the image pickup device 2. Even if the cylindrical wall portion 33 is provided, the integral cylindrical case 3 can be easily molded with a mold. Thus, when the cylindrical case 3 is an integrally molded product, the interval between the imaging element 2 and the lens 5 can be defined with higher accuracy, and the assembly workability is also improved. In the second embodiment, the inner space S2 existing between the image pickup device 2 and the lens 5 is surrounded by the inner cylindrical wall portion 33 of the cylindrical case 3, so that the bottom surface 33a of the inner cylindrical wall portion 33 is provided. Dust contained in the outside air flowing into the internal space S2 can be removed by the concave groove group while the internal space S2 communicates with the external space through the fine concave groove group.

It is sectional drawing of the camera module which concerns on the example of 1st Embodiment of this invention. It is a principal part perspective view which shows the bottom part shape of the base part of the cylindrical case used in the example of 1st Embodiment. It is sectional drawing of the camera module which concerns on the example of 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Image pick-up element 3 Cylindrical case 3a Vent 4 Infrared ray removal filter 5 Lens 30 Lens barrel part 31 Base part 32 Outer wall part 33 Inner cylinder wall part 33a Bottom surface S1, S2 Internal space

Claims (7)

An image pickup device mounted on a substrate, an infrared ray removal filter whose one surface is opposed to the image pickup device, a lens opposite to the other surface of the infrared ray removal filter, and the infrared ray removal filter and the lens are housed to store the image pickup device. A hollow cylindrical case mounted on the substrate so as to cover, and a camera module communicated with an air vent that exposes an internal space existing between the imaging element and the infrared filter. There,
An inner cylindrical wall portion that has a large number of minute concave grooves on the bottom surface and is surrounded by the outer wall portion of the cylindrical case is provided at a location facing the peripheral edge portion of the imaging element inside the cylindrical case. The inner space is surrounded by the inner cylindrical wall portion by bringing the bottom surface of the inner cylindrical wall portion into contact with the peripheral edge portion of the imaging element, and the inner space is interposed through the groove group. Is configured to communicate with the vent hole.   2. The pedestal according to claim 1, wherein the cylindrical case holds the infrared removing filter on a top surface portion and covers the imaging element so as to cover the imaging element, and the lens accommodates the pedestal. A camera module comprising: a lens barrel portion mounted on a portion; and the inner cylinder wall portion is formed on the pedestal portion. An imaging device mounted on a substrate, a lens facing the imaging device with a predetermined interval, and a hollow cylindrical shape mounted on the substrate so as to accommodate the lens and cover the imaging device A camera module comprising a case and communicated with an air vent that exposes an internal space existing between the imaging element and the lens,
An inner cylindrical wall portion that has a large number of minute concave grooves on the bottom surface and is surrounded by the outer wall portion of the cylindrical case is provided at a location facing the peripheral edge portion of the imaging element inside the cylindrical case. The inner space is surrounded by the inner cylindrical wall portion by bringing the bottom surface of the inner cylindrical wall portion into contact with the peripheral edge portion of the imaging element, and the inner space is interposed through the groove group. Is configured to communicate with the vent hole.   4. The camera module according to claim 3, wherein the cylindrical case is an integrally molded product.   5. The camera module according to claim 1, wherein the groove is formed by hairline processing. 6.   6. The camera module according to claim 1, wherein the groove has a groove depth of 1 to 2 microns.   In the description of any one of claims 1 to 6, the notched groove-shaped vent is formed on the bottom surface of the outer wall portion of the cylindrical case, and the vent is positioned on the substrate. A featured camera module.

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