JP2009025698A - Imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device which can be improved in yield by increasing manufacturing easiness. <P>SOLUTION: Since an IR cut filter F disposed between a taking lens 10 and an image sensor 51 is fitted to a case 20 using a fluid 40 having a viscosity of ≥50 cSt at 100°C, the IR cut filter F can be easily separated after being assembled in the case 20, therby even if it is evident that some trouble occurs to the case 20 or IR cut filter F, the both of them are separated to reuse a normal component. Further, even when it is evident that dust etc., sticks to the image sensor 51 after the IR cut filter F is assembled in the case 20, the IR filter F is separated from the case 20 and the image sensor 51 can be cleaned. Furthermore, the fluid is stable even at high temperature and its surface tension deters the IR cut filter F from separating from the case 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus suitable for use with a solid-state imaging device such as a CCD image sensor or a CMOS image sensor.

Mobile phones that have been provided with a photographing function by incorporating an imaging device have become widespread. Also, in order to facilitate the incorporation of shooting functions into small electronic devices such as mobile phones, an optical unit in which an imaging lens is incorporated in advance and a mounting substrate in which a solid-state imaging device and a control circuit are provided are assembled into a unit. A camera module is provided (see, for example, Patent Document 1).
JP 2007-121853 A

  By the way, in the imaging device described in Patent Document 1, an IR cut filter having a function of cutting infrared rays is bonded to a housing using an adhesive. Here, once the IR cut filter is bonded to the casing, separation becomes impossible. Therefore, if any defect occurs in the casing, it must be discarded together with the IR cut filter, resulting in poor yield. In addition, if it is discovered that foreign matter such as dust adheres to the light receiving surface of the image sensor after the IR cut filter is bonded to the housing, the relatively expensive image sensor cannot be discarded. Although it is necessary to clean and reuse, in such a case, the bonded IR cut filter or housing must be destroyed and cleaned, which is laborious and expensive. Furthermore, the adhesive itself for fixing the IR cut filter may become a factor that generates dust after curing.

  The present invention has been made in view of the problems of the related art, and an object of the present invention is to provide an imaging apparatus capable of improving the manufacturability and improving the yield.

  The image pickup apparatus of the present invention is characterized in that an optical element disposed between an image pickup lens and an image pickup element is attached to a housing using a fluid having a viscosity of 50 cSt or more at 100 ° C.

  According to the present invention, since the optical element disposed between the imaging lens and the imaging element is attached to the casing using a fluid having a viscosity of 50 cSt or more at 100 ° C., the optical member is assembled to the casing. Since it can be easily separated after being found, even if it is found that some trouble has occurred in the housing or the optical member after the assembly, both can be separated and only normal parts can be reused. Further, even when it is determined that dust or the like is attached to the image sensor after the optical member is assembled to the housing, the image sensor can be cleaned by separating the optical member from the housing. Furthermore, if it is a fluid which has a viscosity of 50 cSt or more at 100 ° C., it is stable even at high temperatures, and the surface tension suppresses separation of the optical member from the casing. In addition, there is an advantage that it does not become a factor for generating dust and the like unlike an adhesive.

  According to a specific aspect of the present invention, when the fluid is a fluorine-based lubricant, the fluid is chemically stable and hardly undergoes oxidative degradation, and further, the vapor pressure is low, so that the fluid is used in a vacuum environment or a clean room. It is suitable for. However, the present invention is not limited to this. For example, a silicon-based lubricant may be used. As an example of the fluorine-based lubricant, there is a product surface “Varielta” marketed by NOK Cluuba Corporation.

  According to a specific aspect of the present invention, the housing includes a receiving portion for the fluid adjacent to a portion where the imaging lens and the housing slide. Thereby, even if dust or the like is generated by sliding between the imaging lens and the housing, it can be captured by the fluid stored in the receiving portion.

  According to a specific aspect of the present invention, the optical member is preferably an IR cut filter, but is not limited thereto.

  ADVANTAGE OF THE INVENTION According to this invention, the imaging device which can improve manufacture ease and can improve a yield can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an imaging apparatus 50 according to the present embodiment, and FIG. 2 is a cross-sectional view of the configuration of FIG. 1 taken along the line II-II and viewed in the direction of the arrow. As illustrated in FIG. 2, the imaging device 50 includes a CMOS image sensor 51 as a solid-state imaging device having a photoelectric conversion unit 51 a and imaging as an imaging lens that causes the photoelectric conversion unit 51 a of the image sensor 51 to image a subject image. An IR cut filter F, which is an optical member disposed between the lens 10, the image sensor 51, and the imaging lens 10, and an external connection terminal (not shown) that holds the image sensor 51 and transmits and receives electrical signals thereof. And a substrate 52 that is formed integrally.

  In the image sensor 51, a photoelectric conversion unit 51a as a light receiving unit in which pixels (photoelectric conversion elements) are two-dimensionally arranged is formed in the center of a plane on the light receiving side. A processing circuit 51b is formed. The signal processing circuit 51b forms a picture signal output by using a drive circuit unit that sequentially drives each pixel to obtain a signal charge, an A / D conversion unit that converts each signal charge into a digital signal, and the digital signal. It consists of a signal processing unit and the like. A number of pads (not shown) are arranged near the outer edge of the plane on the light receiving side of the image sensor 51, and are connected to the substrate 52 via wires (not shown). The image sensor 51 converts the signal charge from the photoelectric conversion unit 51a into an image signal such as a digital YUV signal, and outputs the image signal to a predetermined circuit on the substrate 52 via a wire (not shown). Here, Y is a luminance signal, U (= R−Y) is a color difference signal between red and the luminance signal, and V (= BY) is a color difference signal between blue and the luminance signal. Note that the image sensor is not limited to the above CMOS image sensor, and other devices such as a CCD may be used.

  The substrate 52 on which the lower end of the housing 20 is placed has a large number of signal transmission pads provided on the surface thereof, which are connected to the wires from the image sensor 51 described above.

  The substrate 52 is connected to an external circuit (for example, a control circuit included in a host device on which the imaging device is mounted) via an external connection terminal (not shown), and a voltage or clock signal for driving the image sensor 51 from the external circuit. And the digital YUV signal can be output to an external circuit.

  The casing 20 made of a light-shielding member has a rectangular tube shape, and is arranged so as to surround the image sensor 51, and the lower end thereof is bonded to the substrate 52 using the adhesive B. The adhesive B is different from the adhesive B that fixes the image sensor 51 to the substrate 52, but the same adhesive B may be used.

  In FIG. 1, an annular portion 20c at the center of the flange portion 20a extending in the direction orthogonal to the optical axis extends from the inner periphery near the lower end of the housing 20 above the image sensor 51, and the housing is formed around the annular portion 20c. A recessed annular portion on the flange portion 20a up to the inner periphery of the body 20 is a receiving portion R in which the fluid 40 is stored. The IR cut filter F is a member formed in, for example, a substantially rectangular shape or a circular shape, and is placed on the annular portion 20 c, and its lower surface touches the surface of the fluid 40. The fluid 40 is a fluorine-based lubricating oil, and comes into close contact with the IR cut filter and has a function of suppressing peeling and deviation against vibration and the like. In this way, by providing the receiving portion R of the fluid 40 so as to extend to the inner periphery of the housing 20, dust generated by sliding between the lens L <b> 3 and the housing 20 can be captured by the fluid 40. Can be suppressed.

  The imaging lens 10 provided in the center of the housing 20 is fixed with an adhesive by joining the flange portions in the order of the first lens L1, the second lens L2, and the third lens L3 from the object side. The lower surface of the flange portion of the third lens L3 closest to the image sensor 51 is in contact with the step portion 20b of the housing 20, and the upper surface is a spring member with respect to the lid member 21 fixed to the upper end of the housing 20. 22 is biased toward the stepped portion 20b.

  Further, a light shielding member 23 is fixed to the upper portion of the flange portion of the first lens L1, thereby preventing unnecessary light from entering the inside of the housing 20 and suppressing the occurrence of ghosts and flares. it can.

  According to the present embodiment, the IR cut filter F disposed between the imaging lens 10 and the image sensor 51 is attached to the housing 20 using the fluid 40 having a viscosity of 50 cSt or higher at 100 ° C. Since the IR cut filter F can be easily separated after being assembled to the housing 20, even after it is found that some trouble has occurred in the housing 20 or the IR cut filter F, the two are separated. Only normal parts can be reused. In addition, when it is determined that dust or the like is attached to the image sensor 51 after the IR cut filter F is assembled to the housing 20, the image sensor 51 is separated from the housing 20 by separating the IR cut filter F. Can be cleaned. Furthermore, if it is the fluid 40 which has a viscosity of 50 cSt or more at 100 ° C., it is stable even at a high temperature, and separation of the IR cut filter F from the housing 20 is suppressed by its surface tension. In addition, there is an advantage that it does not become a factor for generating dust and the like unlike an adhesive.

  A usage mode of the imaging apparatus 50 described above will be described. FIG. 3 is a diagram illustrating a state in which the imaging device 50 is installed in a mobile phone 100 as a mobile terminal. FIG. 4 is a control block diagram of the mobile phone 100.

  In the imaging device 50, for example, the object-side end surface of the housing 20 in the imaging lens is provided on the back surface of the mobile phone 100 (the liquid crystal display unit side is the front surface), and is arranged at a position corresponding to the lower side of the liquid crystal display unit. Established.

  The external connection terminal 54 of the imaging device 50 is connected to the control unit 101 of the mobile phone 100 and outputs an image signal such as a luminance signal or a color difference signal to the control unit 101 side.

  On the other hand, as shown in FIG. 4, the mobile phone 100 controls each unit in an integrated manner, and also supports a control unit (CPU) 101 that executes a program corresponding to each process, and inputs a number and the like with keys. An input unit 60, a display unit 70 for displaying captured images and videos in addition to predetermined data, a wireless communication unit 80 for realizing various information communication with an external server, and a mobile phone 100 By a storage unit (ROM) 91 that stores necessary data such as system programs, various processing programs, and terminal IDs, and various processing programs and data executed by the control unit 101, or processing data, or the imaging device 50 And a temporary storage unit (RAM) 92 that is used as a work area for temporarily storing imaging data and the like.

  When the photographer holding the mobile phone 100 points the optical axis of the imaging lens 10 of the imaging device 50 toward the subject, an image signal is captured by the image sensor 51. When the photographer presses the button BT shown in FIG. 3 at a desired photo opportunity, release is performed, and the image signal is taken into the imaging device 50. The image signal input from the imaging device 50 is transmitted to the control system of the mobile phone 100 and stored in the storage unit 92 or displayed on the display unit 70, and further, video information is transmitted via the wireless communication unit 80. Will be transmitted to the outside.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate.

It is a perspective view of the imaging device 50 concerning this Embodiment. It is sectional drawing which cut | disconnected the structure of FIG. 1 by the arrow II-II line | wire, and looked at the arrow direction. It is a figure which shows the state equipped with the imaging device 50 in the mobile telephone 100 as a portable terminal. 3 is a control block diagram of the mobile phone 100. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Imaging lens 20 Case 20a Flange part 20b Step part 21 Lid member 22 Spring member 23 Light shielding member 40 Fluid 50 Imaging device 51 Image sensor 51a Photoelectric conversion part 51b Signal processing circuit 52 Board | substrate 52a Support flat plate 60 Input part 70 Display part 80 Wireless communication unit 92 Storage unit 100 Mobile phone 101 Control unit B Adhesive BT Button F IR cut filters L1 to L3 Lens

Claims (4)

  An image pickup apparatus, wherein an optical element disposed between an image pickup lens and an image pickup element is attached to a housing using a fluid having a viscosity of 50 cSt or more at 100 ° C.   The imaging apparatus according to claim 1, wherein the fluid is a fluorine-based lubricant.   The imaging apparatus according to claim 1, wherein the casing includes a receiving portion for the fluid adjacent to a portion where the imaging lens and the casing slide.   The imaging apparatus according to claim 1, wherein the optical member is an IR cut filter.

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