JP5116493B2 - Imaging device - Google Patents

Description

    The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus provided with a flexible printed wiring board on which an imaging element is mounted.

    An imaging unit of an electronic device equipped with an imaging function includes an imaging element, a driving circuit that drives the imaging element, a signal processing circuit that processes an output signal from the imaging element, and the like. The drive circuit and the signal processing circuit are usually mounted on a printed wiring board, and it is necessary to electrically connect the image sensor to the drive circuit and the signal processing circuit.

    The printed circuit board on which the drive circuit and the signal processing circuit are mounted has a signal output pattern of the image sensor and an image sensor as a connection wiring for electrically connecting the image sensor and the drive circuit or the signal processing circuit. A drive pulse pattern for driving is formed. The signal output pattern of the image sensor is vulnerable to noise and it is necessary to prevent crosstalk from the drive pulse pattern. In addition, the drive clock has been speeded up due to the recent increase in the number of pixels and functions of the image sensor, and it is necessary to prevent an increase in unnecessary radiation from the drive pulse pattern due to the speedup of the drive clock. In particular, when the approval of the EMI standard cannot be obtained due to unnecessary radiation, the electronic device cannot be sold, which is a serious problem.

In order to solve the above problem, in Japanese Patent Laid-Open No. 10-313178 (Patent Document 1), a multilayer printed wiring board is used, and a power supply layer and a ground layer are arranged in an inner layer. In addition, the drive pulse pattern and the signal output pattern are arranged so as not to overlap each other in plan view, and these patterns are arranged on both outer layers to prevent interference from the drive pulse pattern to the signal output pattern. It is composed.
JP 10-313178 A

    According to the above configuration, since the degree of freedom of pattern routing is high, it is easy to reduce crosstalk between the signal output pattern of the image sensor and the drive pulse pattern. In addition, it is easy to take measures on pattern routing for reducing unnecessary radiation from the drive pulse pattern.

    However, in the above configuration, since a printed wiring board having a multilayer wiring layer is used, it is difficult to give the printed wiring board flexibility. In recent years, with the increase in the number of pixels of an image sensor, the necessity of highly accurately aligning the light receiving surface of the image sensor with respect to the imaging surface of the photographing lens optical system is increasing. For this reason, it is necessary to adjust the position of the image pickup device (adjustment of surface tilt) with respect to the lens barrel.

    Therefore, it is desired to reduce the crosstalk between the signal output pattern and the drive pulse pattern and to reduce unnecessary radiation from the drive pulse pattern without losing the flexibility of the printed wiring board.

    The present invention provides an imaging apparatus in which the influence of crosstalk and unwanted radiation is reduced.

In order to solve the above problem, an imaging apparatus of the present invention is the image pickup element to the first surface mounting, the flexible printed wiring wherein the first surface is a connector to a second surface opposite the mounted An image pickup apparatus having a plate, wherein a first drive signal pattern connected to the image pickup device is formed on the first surface of the flexible printed wiring board, and the first surface of the flexible printed wiring board. A pattern on which a second drive signal pattern connected to the connector is formed is formed on the second surface, and overlaps the second drive signal pattern on the first surface of the flexible printed wiring board. A first ground pattern is formed on the portion, and a second ground pattern is formed on the second surface of the flexible printed wiring board so as to overlap the first drive signal pattern. The first drive signal pattern and the second drive signal pattern are connected by a through hole formed in the flexible printed wiring board, and the through hole is substantially parallel to the optical axis of the imaging device. It is formed in the area | region arrange | positioned so that it may become .

  Other features and objects of the present invention are illustrated in the following examples.

    ADVANTAGE OF THE INVENTION According to this invention, the imaging device which reduced the influence by crosstalk and unnecessary radiation can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

    First, an outline of the imaging apparatus in the present embodiment will be described. FIG. 2 is an external perspective view of the digital camera (imaging device) in the present embodiment.

    In FIG. 2, reference numeral 1 denotes a digital camera. Reference numeral 2 denotes an imaging unit arranged inside the digital camera 1. The imaging unit 2 includes a photographing lens barrel unit 3, a finder unit 4, and an AF auxiliary light unit 5. As shown in FIG. 2, the imaging units 2 are arranged so that each is exposed from an opening provided in the front exterior of the digital camera 1.

    Next, a printed wiring board on which the CCD sensor according to this embodiment is mounted will be described. FIG. 3 is a schematic diagram of a flexible printed wiring board on which a CCD sensor is mounted. FIGS. 3A and 3B show the front surface and the back surface of the flexible printed wiring board, respectively. In this embodiment, the surface of the flexible printed wiring board shown in FIG. 3A is the first surface, and the surface shown in FIG. 3B is the second surface opposite to the first surface. To do.

    In FIG. 3A, reference numeral 10 denotes a flexible printed wiring board (hereinafter referred to as “CCD flexible”) having flexibility. Reference numeral 11 denotes a CCD sensor as a solid-state image sensor. The CCD sensor 11 is mounted on the first surface of the CCD flex 10.

    A buffer circuit 12 amplifies a weak signal output pattern output from the CCD sensor 11. The buffer circuit 12 is mounted on the first surface of the CCD flex 10 in the vicinity of the mounting portion of the CCD sensor 11.

    The CCD flexible cable 10 of this embodiment is a double-sided flexible printed wiring board in which patterns are wired on both sides. On the second surface opposite to the first surface on which the CCD sensor 11 and the buffer circuit 12 are mounted, a board-to-board connector 13 (connection portion) having a fitting portion is mounted. As will be described later, the board-to-board connector 13 is provided for electrical connection with a drive circuit that drives the CCD sensor 11.

    A glass epoxy resin backing 14 is affixed to the back side (first surface) of the area where the board-to-board connector 13 is mounted. By attaching the backing 14 to the CCD flexible printed circuit 10, it is possible to prevent the solder of the mounted connector terminal portion from being peeled off when the board-to-board connector 13 is inserted or removed.

    Next, the assembled state around the CCD flexible cable 10 will be described. FIG. 4 is an exploded perspective view of the digital camera in the present embodiment.

    The CCD sensor 11 is mounted on the first surface of the CCD flex 10 so as to be positioned on the back side of the imaging unit 2 that performs optical processing. The CCD flex 10 is provided with a metal plate 15 on the first surface on which the CCD sensor 11 is mounted. The plate 15 is formed so as to surround the periphery of the CCD sensor 11. The plate 15 is adhered to the CCD flexible film 10 using an adhesive such as an ultraviolet curable resin, and is securely fixed by being screwed to the imaging unit 2.

    At this time, surface tilt adjustment of the CCD sensor 11 is performed. By this surface tilt adjustment, the position is regulated so that the light receiving surface of the CCD sensor 11 is attached to the correct position with respect to the optical axis of the imaging unit 2. The imaging unit 2 to which the CCD flex 10 is attached is securely fixed by being screwed to the chassis 30. The chassis 30 is screwed with a battery box 40 into which a battery is inserted.

    The main printed wiring board 20 (hereinafter referred to as “main board 20”) fits a pair of positioning dowels 41 protruding from the battery box 40 and a pair of positioning holes 21 provided in the main board 20. Is positioned by. The main board 20 is securely fixed to the three screw holes 31 provided in the chassis 30 by screwing with the through holes 22 provided in the main board 20.

    On the main board 20, a board-to-board connector 23 having a fitting portion and an IC 24 for driving the CCD sensor 11 and performing signal processing are mounted on the same surface. The IC 24 mainly includes a drive circuit that drives the CCD sensor 11 and a signal processing circuit that processes an output signal from the CCD sensor 11. When the board-to-board connector 13 mounted on the CCD flex 10 and the board-to-board connector 23 mounted on the main board 20 are fitted, the CCD sensor 11 and the IC 24 (drive circuit, signal processing circuit) are electrically connected. Connected to.

    As described above, the drive circuit is mounted on the main substrate 20 on the same surface as the connection surface of the main substrate 20 that is connected to the substrate-to-substrate connector 13 of the CCD flex 10. For this reason, wiring that does not pass through holes can be formed in the main board 20, and signal deterioration on the main board can be suppressed.

    In a state where the digital camera 1 is assembled, the main board 20 is disposed on the front surface of the digital camera 1, that is, on the subject side. On the other hand, the CCD sensor 11 mounting portion (first region) of the CCD flex 10 is disposed on the photographer side, which is the back surface of the imaging unit 2. For this reason, the CCD flex 10 includes the first bent portion 16a serving as a boundary between the first region and the second region, and the second bent portion 16b serving as a boundary between the second region and the third region. Have.

    The first area of the CCD flex 10 is a plane portion on which the CCD sensor 11 and the buffer circuit 12 are mounted. The second region is a flat surface portion in which the first region is bent to the front surface of the digital camera 1 by the first bent portion 16a. The third region is a flat portion where the second region is bent by the second bent portion 16b and the board-to-board connector 13 is mounted.

    The CCD flex 10 is bent from the first area located on the back surface of the imaging unit 2 by the first bent portion 16a so as to be parallel to the optical axis direction of the digital camera 1 to form a second area. The second region passes between the lens barrel unit and the battery box, and is electrically connected to the main board 20 by being further bent by the second bent portion 16b.

    A backlight frame 101 holding the LCD unit 100 is disposed on the back surface (second surface) of the first region where the CCD sensor 11 is mounted. The backlight frame 101 is fixed to the chassis 30. When these are assembled, there is almost no clearance between the CCD flexible cable 10 and the backlight frame 101.

    Next, the configuration of the image input unit including the CCD sensor 11 will be described. FIG. 5 is a configuration diagram of an image input unit of the digital camera in the present embodiment.

    In FIG. 5, reference numeral 55 denotes a CCD sensor driving unit. The CCD sensor drive unit 55 operates as a drive circuit that drives the CCD sensor 11. Reference numeral 52 denotes a correlated double sampling unit (hereinafter referred to as “CDS unit”). Reference numeral 53 denotes an analog-digital conversion unit (hereinafter referred to as “ADC unit”), and 54 denotes a digital signal processing unit. The CDS unit 52, the ADC unit 53, and the digital signal processing unit 54 operate as a signal processing circuit that processes an output signal from the CCD sensor 11.

    The CCD sensor 11 is driven by outputting signals such as a horizontal drive pulse, a reset gate pulse, a vertical drive pulse, and an electronic shutter pulse from the CCD sensor drive unit 55. The CCD sensor 11 converts the optical image of the subject into an electrical signal based on drive control by the CCD sensor drive unit 55.

    The electrical signal output from the CCD sensor 11 includes a reset noise component during CCD transfer. For this reason, a CDS unit 52 is provided at the subsequent stage of the CCD sensor 11 to remove a reset noise component generated during CCD transfer. The output pixel signal that is an analog signal output from the CDS unit 52 is converted into a digital signal by the ADC unit 53. The digital signal output from the ADC unit 53 is transmitted to the digital signal processing unit 54.

    In this embodiment, the CDS unit 52, the ADC unit 53, and the CCD sensor driving unit 55 are configured as an IC 24. However, the present invention is not limited to such a configuration, and the CDS unit 52, the ADC unit 53, and the CCD sensor driving unit 55 may be configured as separate ICs or discrete components, respectively.

    FIG. 6 shows the basic configuration of the CDS unit.

    In FIG. 6, the CDS unit 52 includes a pulse signal (hereinafter referred to as “SHP signal”) that samples and holds a feed-through period for holding a reset level, and a pulse signal (hereinafter referred to as “SHP signal”) that samples and holds a video signal output period. SHD signal ") is input. The CDS unit 52 includes sample and hold circuits 61, 62 and 63, and a differential amplification unit 64. The sample and hold circuits 61 and 62 are connected in series.

    The SHP signal is input to the sample hold circuit 61. The SHD signal is input to the sample and hold circuits 62 and 63. With such a configuration, the output signal from the CCD sensor 11 is sampled and held based on the SHP signal and the SHD signal. The output signals of the sample and hold circuits 62 and 63 are input to the difference amplifying unit 64, and the difference amplifying unit 64 calculates the difference between these output signals. The sample and hold circuits 61, 62, and 63 track analog signals, and when a hold command is given, hold the value of the input signal at the moment when the hold command is executed. That is, the sample hold circuits 61, 62, and 63 have a function as an analog storage device.

    FIG. 7 shows the control timing of the sample and hold circuit.

    As shown in FIG. 7, one pixel period of the signal read from the CCD sensor 11 includes a reset unit, a feedthrough unit, and a video signal unit. When both the SHP signal and the SHD signal are low (L), the signal is reset from the signal read from the CCD sensor 11. When the SHP signal is high (H) and the SHD signal is low, it becomes a feed-through portion of the signal read from the CCD sensor 11. When the SHP signal is low (L) and the SHD signal is high (H), the video signal portion of the signal read from the CCD sensor 11 is obtained. According to the control timing shown in FIG. 7, the levels of the feedthrough part and the video signal part are respectively extracted.

    FIG. 8A is a configuration diagram of a typical sample-and-hold circuit, and FIG. 8B shows input / output signals in the sample-and-hold circuit.

    As shown in FIG. 8A, the sample and hold circuit is generally composed of an analog switch 82 and a capacitor 83. 8B, the analog switch 82 is turned on to charge the input signal to the capacitor 83 (sample mode), and the analog switch 82 is turned off to hold the voltage charged in the capacitor 83. (Hold mode).

    The input buffer 81 reduces the influence on the input signal source, and the output buffer 84 prevents discharge due to load resistance. The time for which the analog switch 82 is turned on, that is, the sampling time, is the time necessary for charging the capacitor 83 with the input signal. By ensuring sufficient sampling time, the random noise component of the input signal can be reduced by integration, and an output signal with a high signal-to-noise ratio can be obtained.

  FIG. 9 shows a schematic configuration of an interline solid-state imaging device as an example of the CCD sensor 11. As shown in FIG. 9, in the interline solid-state imaging device, a plurality of pixels are arranged in a matrix. Note that the interline solid-state imaging device in FIG. 9 has the number of pixels of 14 horizontal pixels and 10 vertical pixels. However, the number of pixels is not limited to this.

  In FIG. 9, reference numeral 91 denotes a photosensitive pixel that receives light from a subject and performs photoelectric conversion. Reference numeral 92 denotes an optical black pixel in which the photosensitive pixel is shielded from light. Reference numeral 93 denotes a vertical charge transfer element, 94 denotes a horizontal charge transfer element, 95 denotes an output unit, and 96 denotes a signal output terminal.

  The signal charge of the pixel is read to the vertical charge transfer element 93 by a read pulse. The signal charges read to the vertical charge transfer element 93 are sequentially supplied in the direction of the horizontal charge transfer element 94 by the respective four-phase drive pulses φV1, φV2, φV3, and φV4 applied to the transfer electrodes V1, V2, V3, and V4. Transferred.

  The horizontal charge transfer element 94 sequentially outputs the signal charges for one horizontal row transferred from the vertical charge transfer element 93 by respective two-phase drive pulses φH1 and φH2 applied to the transfer electrodes H1 and H2. Forward to. The signal charges are transferred to the floating capacitor of the output unit 95 for each pixel by the two-phase drive pulses φH1 and φH2. Further, a signal for one pixel is supplied from the floating capacitor to the output buffer and converted into a voltage signal, and a video signal for each pixel is sequentially output from the signal output terminal 96. The floating capacitor is cleared by a reset pulse every time a signal of one pixel is output.

  As described above, the output signal from the CCD sensor 11 has, for each pixel, a reset component generated by the reset operation of the floating capacitor, a feed-through portion where the correlation noise of the reset pulse is superimposed, and a video signal portion. The CDS unit 52 obtains the difference between the level of the feedthrough portion and the level of the video signal portion of the output signal from the CCD sensor 11. As a result, the CDS unit 52 operates as a noise removal circuit that removes the correlated noise component from the video signal.

  Next, a wiring method of the horizontal drive pulse pattern 17 in the CCD flexible board 10 will be described.

  FIG. 1 is a schematic diagram of a CCD flex 10 on which a horizontal pulse drive pattern is formed. FIG. 1A shows a first surface of the CCD flex 10, and FIG. 1B shows a second surface opposite to the first surface of the CCD flex 10. FIG. 1C shows only the second region on the first surface of the CCD flex 10.

  As shown in FIGS. 1A to 1C, the CCD flex 10 in this embodiment is a double-sided flex. That is, components are mounted on both sides of the first surface and the second surface opposite to the first surface to form a pattern. In particular, in the CCD flex 10, the mounting surface of the CCD sensor 11 and the mounting surface of the board-to-board connector 13 are different. The CCD sensor 11 is mounted on the first surface of the CCD flex 10. On the other hand, the board-to-board connector 13 is mounted on the second surface of the CCD flex 10.

  For this reason, when a wiring pattern is formed to electrically connect the CCD sensor 11 and the board-to-board connector 13, the wiring pattern surface is changed at least once via a wiring changing portion such as the through hole 19. There is a need to. An impedance change occurs between the through hole 19 and the wiring pattern before and after the through hole 19. Such a change in impedance can be a noise source that generates unwanted radiation.

    Further, since the horizontal drive pulse pattern is a high-speed clock, unnecessary radiation is generated. For this reason, there is a possibility of adversely affecting EMI (Electromagnetic Interference). In addition, when there is an electrically unstable metal member in the vicinity of the horizontal drive pulse pattern, noise may occur in the horizontal drive pulse pattern due to the influence of the metal member.

    The output signal from the CCD sensor 11 is a weak signal. For this reason, there is a concern about crosstalk between the signal output pattern and the horizontal drive pulse pattern. In particular, such crosstalk becomes conspicuous when the signal output pattern and the horizontal drive pulse pattern are superimposed on each other, that is, when wiring is performed at opposite positions on both sides of the CCD flex 10. For this reason, it is desirable that the horizontal drive pulse pattern formed on the CCD flex 10 is guarded by a GND pattern (ground pattern) formed on the CCD flex 10.

    Thus, in this embodiment, the drive signal pattern is a horizontal drive pulse pattern of the CCD sensor. For this reason, the GND pattern (grounding pattern) 18 is formed at a position facing the horizontal drive pulse pattern, which is a high-speed clock, among the drive pulse patterns, and therefore, more effectively suppressing unwanted radiation and crossing with the signal output pattern. Talk reduction is possible.

    When an EMI problem occurs in a digital camera, it is possible to take measures at the initial stage of development by changing the pattern or adding capacitors and coils to the wiring of the noise generation source. On the other hand, when problems occur in the middle or later stages of development, it is often difficult to take measures by changing patterns or adding mounting components. For this reason, a countermeasure is performed by sticking a shield sheet or a radio wave absorber obtained by laminating a copper foil sheet to a noise generation source.

    In recent digital cameras, there is a strong demand for thin camera bodies. For this reason, the problem of EMI occurs in the middle and later stages of development, and when a shield sheet or a radio wave absorber is added, the clearance in the thickness direction inside the digital camera often does not assume additional parts. For this reason, there is a high possibility that countermeasure parts cannot be inserted in the direction in which the thickness of the camera body increases.

    On the other hand, the vertical and horizontal directions of the camera often have a relatively large space due to the increase in size of the LCD. For this reason, it is desirable to add the EMI countermeasure component in parallel with the optical axis surface of the digital camera.

  From the above, in the present embodiment, the through hole 19 of the horizontal drive pulse pattern 17 that can be a noise generation source in EMI is arranged in the second region where the CCD flex 10 is parallel to the optical axis direction of the camera. Here, “parallel” is a concept including not only being in parallel with the optical axis direction in a strict sense but also being substantially parallel. As a result, when a shield sheet or a radio wave absorber is required in the through hole 19 portion of the horizontal drive pulse pattern 17 for EMI countermeasures, it is not in the thickness direction of the camera body but in the lateral direction of the camera having a relatively clearance. It becomes possible to insert.

  As described above, in this embodiment, the second area of the CCD flexible in which the through hole is formed is a plane arranged in parallel with the optical axis direction of the imaging unit. According to such a configuration, when a shield sheet or a radio wave absorber is added to the through hole as a countermeasure against unwanted radiation, the additional member is added to a plane parallel to the optical axis direction. For this reason, it becomes possible to take measures against unnecessary radiation without increasing the thickness direction of the imaging device.

  Further, the horizontal drive pulse pattern 17 from the portion where the board-to-board connector 13 is mounted to the through hole 19 is formed so as to pass through the surface (second surface) inside the camera of the CCD flex 10. In addition, a GND pattern 18 is formed at a position (a portion overlapping with projection) facing the horizontal drive pulse pattern 17 on the surface opposite to the surface on which the horizontal drive pulse pattern 17 is wired.

  Here, in this embodiment, when the CCD flexible board 10 and the main board 20 are electrically connected, the fitting type board-to-board connectors 13 and 23 are used. However, the present invention is not limited to this, and other connection portions such as an FPC connector can be used.

  When an FPC connector is used as the connection portion, when the CCD flexible cable 10 is inserted into the FPC connector, an operation for pulling it toward the insertion opening is generated. For this reason, when using the FPC connector, it is necessary to suppress the waist of the CCD flexible cable 10 in the vicinity of the connector terminal portion. Therefore, the pattern on the surface opposite to the connector terminal surface is eliminated and the coverlay film is opened to reduce the total thickness of the CCD flex 10.

  On the other hand, when the board-to-board connectors 13 and 23 are used as the connection portions as in this embodiment, there is no work of pulling the connector toward the front when the CCD flexible cable 10 is assembled. For this reason, the GND pattern 18 can be wired to the back surface of the connector land portion. As a result, in the horizontal drive pulse pattern 17 from the through hole 19 to the connector land portion, the GND pattern 18 is formed in all regions at the opposite positions on the surface opposite to the surface on which the horizontal drive pulse pattern is wired. Can do. As a result, since unnecessary radiation from the horizontal drive pulse pattern 17 is reliably shielded by the GND pattern 18, it can be more effectively prevented from being radiated to the outside from the front surface of the camera.

    As described above, in this embodiment, the board-to-board connector 13 having the fitting portion is used as the connection portion of the CCD flexible cable 10. In addition, the GND pattern 18 is formed in all portions facing the drive signal pattern except for the through hole 19. For this reason, the entire region where the drive pulse pattern is formed can be guarded by the GND pattern, and it is possible to more effectively suppress unwanted radiation and reduce crosstalk with the signal output pattern.

  The horizontal drive pulse pattern 17 whose wiring surface is changed by a through hole 19 provided in a plane parallel to the camera optical axis direction of the CCD flex 10 passes through the inside of the camera and is connected to the CCD sensor 11. Then, with respect to the horizontal drive pulse pattern from the through hole 19 to the land portion of the CCD sensor 11, all the regions at positions facing the horizontal drive pulse pattern 17 on the surface opposite to the wiring surface of the horizontal drive pulse pattern 17 are provided. The GND pattern 18 is formed.

  The backlight frame 101 is difficult to provide a screw-fastening portion in a digital camera that is required to be reduced in size and thickness, and is often assembled by providing a locking portion in the chassis 30. For this reason, the electrical connection between the chassis 30 and the backlight frame 101 may not be stable, and the backlight frame 101 may become electrically unstable.

  Even in such a situation, an electrically stable GND pattern 18 can be provided between the horizontal drive pulse pattern 17 and the backlight frame 101 as in this embodiment. For this reason, it is possible to prevent noise from jumping from the backlight frame 101 to the horizontal drive pulse pattern 17.

    Further, the entire area from the connector land portion of the horizontal drive pulse pattern 17 to the land portion of the CCD sensor 11 is shielded by the GND pattern 18. For this reason, it is possible to prevent a weak signal output pattern from overlapping the horizontal drive pulse pattern. Thereby, crosstalk between the signal output pattern and the horizontal drive pulse pattern can be reduced.

    Next, a case where an EMI countermeasure component is added to the through hole 19 of the horizontal drive pulse pattern 17 will be described. FIG. 10 is a schematic diagram of a CCD flex provided with a radio wave absorber.

    The horizontal drive pulse pattern 17 is a high-frequency rectangular wave of 20 to 50 MHz. For this reason, there is a possibility that a high-frequency signal cannot follow the pattern in a place where an abrupt pattern change and impedance change occur, such as the through hole 19. As a result, the through hole 19 often becomes a noise generation source, and it is considered that EMI deteriorates.

    In such a case, unnecessary radiation can be prevented by attaching a shield sheet or a radio wave absorber to the CCD flexible cable 10 so as to cover the through hole 19 which is a noise generation source. In this embodiment, as shown in FIG. 10, the radio wave absorber 102 (sheet member) is attached so as to cover all the through holes 19 of the horizontal drive pulse pattern 17.

    As described above, in the present embodiment, the sheet member (radio wave absorber 102) for absorbing radio waves is provided in the CCD flex 10 around the through hole 19. For this reason, it is possible to suppress unnecessary radiation from the through hole.

    FIG. 11 is a perspective view showing the imaging unit in the tele state.

  As shown in FIG. 11, the cam plate 110 for adjusting the lens position of the viewfinder rotates and protrudes from the imaging unit 2 at the tele end position of the zoom operation. If the radio wave absorber 102 affixed to the cam plate 110 and the CCD flex 10 is disposed at a position where they overlap in the protruding direction of the cam plate 110, there is a possibility that the cam plate 110 and the radio wave absorber 102 interfere during zoom operation. . For this reason, there is a possibility of causing problems while repeating tele and wide operations. Therefore, the portion of the through hole 19 to which the shield sheet or the radio wave absorber is attached is disposed at a position where it does not overlap with the component such as the cam plate 110 whose position changes and protrudes when the camera is used. Is desirable.

  As described above, the imaging unit 2 according to the present exemplary embodiment includes components such as the cam plate 110 that protrude during the zoom operation. The through hole 19 is disposed at a position where it does not overlap with the component in the protruding direction of the component. For this reason, when a shield sheet or a radio wave absorber is added to the through hole as a countermeasure against unwanted radiation, the unwanted radiation countermeasure component can be arranged at a position where it does not interfere with a component protruding during the zoom operation.

  As described above, according to the present embodiment, the drive pulse pattern of the image sensor, which is a high-speed clock that can be a source of unwanted radiation, can be guarded by the GND pattern, and unwanted radiation can be suppressed and crosstalk with the signal output pattern can be reduced. It becomes possible. Further, by guarding the drive pulse pattern with the GND pattern, it is possible to suppress noise from peripheral components from jumping into the drive pulse pattern.

  In addition, since the drive pulse of the image sensor is a high frequency rectangular wave of 20 to 50 MHz, a high frequency signal cannot follow the pattern and becomes a noise generation source in a place where an abrupt pattern change and impedance change such as a through hole occur. There are many cases. For this reason, a through-hole is provided in the bent plane with respect to the plane on which the imaging element is mounted. Thereby, when applying the CCD flexible to the electronic device, the through hole can be arranged at a position away from the exterior of the electronic device, which leads to suppression of unnecessary radiation.

  In addition, a drive pulse pattern of the image sensor, which is a high-speed clock that can be a source of unnecessary radiation, can be wired on the CCD flexible cable so as to be on the inner surface of the image pickup apparatus. For this reason, it is possible to suppress unnecessary radiation from being emitted outside the imaging apparatus.

  The present invention has been specifically described with reference to the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the technical idea of the present invention.

  For example, in the above-described embodiment, a digital camera has been described as an example. However, the present invention can be applied to any imaging device including a video camera.

  In the present embodiment, a fitting type board-to-board connector was used as a method of connecting the CCD flexible board and the main board. However, instead of this, it is also possible to provide a terminal portion with a pattern exposed on the side of the CCD flexible cable and insert it into an FPC connector mounted on the main board for electrical connection. It is also possible to apply a connection method using an anisotropic conductive film.

It is a schematic diagram of the flexible printed wiring board in which the horizontal pulse drive pattern in a present Example was formed. It is an external appearance perspective view of the digital camera in a present Example. It is a schematic diagram of the flexible printed wiring board with which the CCD sensor in a present Example was mounted. It is a disassembled perspective view of the digital camera in a present Example. It is a block diagram of the image input part of the digital camera in a present Example. It is a basic block diagram of the CDS part in a present Example. It is a figure which shows the control timing of the sample hold circuit in a present Example. (A) It is a block diagram of the typical sample hold circuit in a present Example. (B) An input / output signal of the sample hold circuit. It is the schematic which shows an example of the CCD sensor in a present Example. It is a schematic diagram of the flexible printed wiring board provided with the electromagnetic wave absorber in a present Example. It is a perspective view which shows the imaging unit in the tele state in a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital camera 2 Imaging unit 3 Shooting lens barrel unit 4 Finder unit 5 AF auxiliary light part 10 Flexible printed wiring board (CCD flexible)
11 CCD sensor 12 Buffer circuit 13, 23 Substrate-to-board connector 14 Backing 15 Plate 16a First bent portion 16b Second bent portion 17 Horizontal drive pulse pattern 18 GND pattern (ground pattern)
19 Through hole 20 Main printed wiring board (main board)
21 Positioning hole 22 Through hole 24 IC
30 Chassis 31 Screw hole 40 Battery box 41 Positioning dowel 52 Correlated double sampling section (CDS section)
53 Analog-to-digital converter (ADC)
54 Digital signal processing unit 55 CCD sensor driving unit 61, 62, 63 Sample hold circuit 64 Differential amplification unit 81 Input buffer 82 Analog switch 83 Capacitor 84 Output buffer 91 Photosensitive pixel 92 Optical black pixel 93 Vertical charge transfer element 94 Horizontal charge transfer element 95 Output unit 96 Signal output terminal 100 LCD unit 101 Backlight frame 102 Radio wave absorber 110 Cam plate

Claims (5)

An imaging device having a flexible printed wiring board in which an imaging element is mounted on a first surface and a connector is mounted on a second surface opposite to the first surface,
A first drive signal pattern connected to the image sensor is formed on the first surface of the flexible printed wiring board, and the second surface of the flexible printed wiring board is connected to the connector. A pattern is formed in which a second drive signal pattern to be connected is formed,
On the first surface of the flexible printed wiring board, a first ground pattern is formed in a portion overlapping the second drive signal pattern, and on the second surface of the flexible printed wiring board, A second grounding pattern is formed in a portion overlapping the first driving signal pattern;
The first drive signal pattern and the second drive signal pattern are connected by a through hole formed in the flexible printed wiring board,
The through hole, an imaging device according to claim Rukoto formed in a region which is arranged substantially parallel to the optical axis of the imaging device. The imaging apparatus according to claim 1 , wherein the driving signal pattern is a horizontal driving pulse pattern of the imaging element. The connector, imaging apparatus according to claim 1 or 2, characterized in that a board-to-board connector provided with a fitting portion. Wherein the flexible printed wiring board, wherein the periphery of the through hole, an imaging device according to any one of claims 1 to 3, characterized in that the sheet member for absorbing radio waves is provided. The imaging device includes an imaging unit that performs optical processing, and the imaging unit includes a component that protrudes during a zoom operation,
The through holes in the projecting direction of the component, an imaging apparatus according to claim 4, characterized in that it is formed in a position that does not overlap with the part.