JP2004282778A - Imaging apparatus, signal processing instrument, and signal processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a miniaturized, thin, and lightweight imaging apparatus, and also to facilitate incorporation and operation. <P>SOLUTION: A CCD bare chip 12 which performs photoelectric conversion of light in which an image is formed by an imaging lens 4 provided to a holder 2 and outputs a picture signal is equipped in a device board 1. The imaging lens 4 is provided in the holder 2. The exterior has a diaphram effect masking ambient light and is set to package 2A masking light from outside. Also, in the package 2A, a circular hole 3 is provided to the imaging lens 4 for receiving the light from an object. The holder 2 is mounted on the board 1 and thus the imaging apparatus is constituted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image pickup apparatus, a signal processing apparatus, and a signal processing method, and more particularly, to an image pickup apparatus and a signal processing apparatus that can provide an image capturing apparatus, for example, a video camera or the like, which can be reduced in size and weight and provided at a low price. And a signal processing method.

  FIG. 54 shows an example of a configuration of a conventional video camera. This video camera includes a lens module 101 and a camera body 111. The lens module 101 includes an imaging lens 102 including a focus lens 104, and an iris adjustment mechanism 103. The camera body 111 includes an optical LPF (low-pass filter) 112, an image sensor 113, and a camera processing circuit 114. Have been.

  The light from the subject incident on the imaging lens 102 is emitted to the image sensor 113 via the iris adjustment mechanism 103 and the optical LPF 112, whereby an image of the subject is formed on the light receiving surface of the image sensor 113. It is imaged. The image sensor 113 includes, for example, a charge-coupled device (hereinafter, appropriately referred to as a CCD), photoelectrically converts light as an image of the subject received on its light receiving surface, and converts an image signal corresponding to the subject obtained as a result. , To the camera processing circuit 114. In the camera processing circuit 114, predetermined signal processing is performed on the image signal from the image sensor 113, and thereafter, the image signal is recorded on a recording medium such as a video tape, or is output and displayed on a monitor, for example. Further, it is supplied to a computer or the like for performing predetermined processing.

  A drive signal is supplied from the camera processing circuit 114 to the image sensor 113, and the image sensor 113 performs a predetermined process such as outputting an image signal according to the drive signal. The iris adjustment mechanism 103 adjusts the brightness of an image formed on the image sensor 113, and blocks peripheral rays unnecessary for image formation emitted from the image forming lens 102. It has been made. Further, the focus lens 104 adjusts the focus of an image formed on the image sensor 113. The optical LPF 112 is an optical element having a different refractive index depending on the polarization plane of light incident thereon, and is made of, for example, crystalline quartz having optical anisotropy, and has a spatial frequency of light from the focus lens 104. High-frequency components are suppressed, and thereby, aliasing distortion generated in the image sensor 113 is reduced.

  By the way, when a video camera is used, for example, for inputting an image to a computer or for monitoring a car, or when applied to a so-called video phone or a video conference system, the video camera is obtained from the video camera. It is not so required that the image be of high quality. That is, a video camera is required that is easy to install and handle, even if the image quality is not so high.

  However, conventionally, in order to easily assemble and handle, optical adjustment is required at the time of manufacturing, which complicates the manufacturing process, increases the size of the apparatus, and increases its price.

  Further, in a conventional video camera, an optical LPF 112 is required as shown in FIG. 54 in order to limit the spatial frequency of light incident on the image sensor 113. The thickness had to be proportional. For this reason, when an image sensor with a small pixel pitch is used as the image sensor 113, the price of the image sensor 113 increases, and when an image sensor with a large pixel pitch is used, the optical LPF 112 having a large thickness d is used. It is necessary to provide it, and the device becomes large.

  Therefore, a video camera having a configuration as shown in FIG. 55 is known as a more compact and lower cost video camera. In this example, a CCD image sensor 403 is fixed on a substrate 404. Further, one imaging lens 401 is fixed to the lens barrel 402, and the lens barrel 402 is fixed to the substrate 404. Various components 405 are attached to the back side of the substrate 404.

  In the example of FIG. 55, the illustration of the configuration such as the adjustment mechanism for adjusting the light amount is omitted.

Here, the CCD image pickup device 403 is configured as shown in FIG. That is, the CCD image pickup device 403 includes a CCD bare chip 403A that photoelectrically converts input light. The CCD bare chip 403A has a color filter (not shown) on its light incident surface side that allows only light of predetermined wavelengths of R, G, and B (which may be complementary colors) to pass. The CCD bare chip 403A is housed inside a package 403B made of plastic or the like, and a cover glass 403C is arranged at an upper end of the package 403B.
JP-A-63-314077 JP-A-63-314078 JP-A-63-314081

  However, in the configuration example shown in FIG. 55, the distance from the upper end of the imaging lens 401 to the upper surface of the CCD image sensor 403 is about 30 mm, the thickness of the CCD image sensor 403 is 5 mm, and The distance to the lower end of 405 is about 15 mm, and the total is about 50 mm.

  Therefore, there is a problem that the configuration as shown in FIG. 55 cannot be incorporated in, for example, a PC card and used in a portable personal computer or the like.

  The present invention has been made in view of such a situation, and it is an object of the present invention to provide a small and lightweight device which is easy to assemble and handle and can be provided at a low price.

  The image pickup apparatus of the present invention is provided with at least one image forming lens for forming an image of light, has an aperture effect of blocking peripheral rays, and has an exterior holder that blocks external light, and at least an image forming lens. An imaging apparatus comprising: a substrate on which a photoelectric conversion element that photoelectrically converts an imaged light and outputs an image signal is mounted, wherein the holder and the substrate are integrated.

  According to the method of manufacturing an imaging device of the present invention, a photoelectric conversion element that photoelectrically converts incident light and outputs an image signal is mounted on a substrate, and one imaging lens that forms light on the photoelectric conversion element. A step of forming a portion that blocks marginal rays, and a step of integrating the imaging lens with the substrate.

  The imaging device of the present invention includes one imaging lens that forms light, and at least a substrate on which a photoelectric conversion element that photoelectrically converts light formed by the imaging lens and outputs an image signal is mounted. When the F-number defined by the pupil diameter D of the imaging lens and the focal length f is F, the photoelectric conversion element has an effective pixel pitch of 1 / (200F) of the effective imaging area. ) Is set to a larger value.

  An imaging apparatus according to an aspect of the invention includes one imaging lens that forms light, and a photoelectric conversion element that photoelectrically converts light formed by the imaging lens and outputs an image signal. A part thereof is in direct contact with the photoelectric conversion element.

  The imaging device of the present invention includes a photoelectric conversion element that photoelectrically converts light incident on a light receiving surface and outputs an image signal, and an A / D converter that A / D converts an image signal output from the photoelectric conversion element. And the photoelectric conversion element and the A / D converter are incorporated in one package.

  A signal processing device according to the present invention is a signal processing device for processing digital image data obtained by A / D converting an image signal output from a charge-coupled device, wherein the image data is output by the charge-coupled device. When the image signal is A / D-converted at the timing of a clock having a half cycle, a delay unit for delaying the image data by one clock, a delay unit for the image data and an output of the delay unit. It is characterized by comprising arithmetic means for calculating the difference, and output means for outputting every other difference output from the arithmetic means.

  A signal processing method according to the present invention is a signal processing method for processing digital image data obtained by A / D converting an image signal output from a charge-coupled device, wherein the image data is output from the charge-coupled device. A step of delaying the image data by one clock when the image signal is A / D converted at a clock timing having a half cycle of the cycle; The method is characterized by comprising a step of calculating a difference from data and a step of outputting every other difference.

  The imaging adapter device of the present invention includes a housing detachably mounted on the information processing device, and an imaging device housed in the housing, and the imaging device is provided with one imaging lens that forms light. Has a diaphragm effect of blocking peripheral rays, a holder of an exterior that blocks external light, and a photoelectric conversion element that photoelectrically converts light formed by the imaging lens and outputs an image signal, It is characterized by comprising a holder and an integrated substrate.

  An information processing apparatus according to the present invention includes a capturing unit that captures an image signal from an imaging device, and a processing unit that processes the image signal captured by the capturing unit.

  An information processing method according to the present invention includes a step of capturing an image signal from an imaging device and a step of processing the captured image signal.

  In the image pickup apparatus of the present invention, the holder has an aperture effect of blocking peripheral light, and is configured to block external light, and the holder has at least one image for forming light. A lens is provided. At least a photoelectric conversion element that photoelectrically converts light formed by the image forming lens and outputs an image signal is mounted on the substrate. The holder and the substrate are integrated.

  In the method of manufacturing an image pickup device according to the present invention, one image forming device that photoelectrically converts incident image-formed light and forms an image on the photoelectric conversion element is mounted on a substrate on which a photoelectric conversion element that outputs an image signal is mounted. A holder provided with an image lens and having an aperture effect of blocking peripheral light rays and of an exterior that blocks external light is mounted.

  In the imaging device of the present invention, the effective pixel pitch of the photoelectric conversion element is set to a value larger than 1 / (200F) of the imaging effective area.

  In the imaging apparatus according to the aspect of the invention, a part of one imaging lens that forms an image of light is in direct contact with a photoelectric conversion element that photoelectrically converts light formed by the imaging lens and outputs an image signal. It has been done.

  In the imaging device according to the present invention, the photoelectric conversion element photoelectrically converts light incident on the light receiving surface and outputs an image signal. The A / D converter is configured to A / D convert an image signal output from the photoelectric conversion element. These photoelectric conversion elements and A / D converters are incorporated in one package.

  In the signal processing device and the signal processing method according to the present invention, the image data is delayed by one clock, the difference between the image data and the image data delayed by one clock is calculated, and the difference is output every other one. It has been made to be.

  In the imaging adapter device of the present invention, the imaging device is housed in the housing, and the imaging device has a holder having an imaging lens and a diaphragm integrated with the substrate on which the photoelectric conversion element is mounted.

  In the information processing apparatus and the information processing method according to the present invention, an image signal output from a photoelectric conversion element of an imaging device housed in a housing is captured and processed.

  ADVANTAGE OF THE INVENTION According to this invention, the exterior has the stop effect which interrupts external light and blocks a peripheral ray, and the holder provided with one imaging lens which images light, and at least an imaging lens And a substrate on which a photoelectric conversion element that outputs an image signal by photoelectrically converting the light formed by the method is integrated. Therefore, it is possible to reduce the size, thickness, and weight of the imaging device, and to easily incorporate and handle the imaging device. Further, a photoelectric conversion element with a small number of pixels can be used.

  According to the present invention, since the pitch of the effective pixels is set to a value larger than 1 / (200F) of the effective imaging area, it is possible to realize an imaging device that can be reduced in thickness at low cost.

  According to the present invention, a part of one imaging lens that forms an image of light is in direct contact with a photoelectric conversion element that photoelectrically converts light formed by the imaging lens and outputs an image signal. Therefore, it is possible to reduce the size, thickness, and weight of the imaging device, and to easily incorporate and handle the imaging device. Further, not only can a photoelectric conversion element having a small number of pixels be used, but also optical adjustment between the imaging lens and the photoelectric conversion element can be omitted.

  According to the present invention, the photoelectric conversion element and the A / D converter are incorporated in one package. Therefore, it is possible to reduce the size, thickness, and weight of the imaging device, and to easily incorporate and handle the imaging device. Further, not only can a photoelectric conversion element having a small number of pixels be used, but also a small-sized imaging device that outputs digital image data can be provided.

  According to the present invention, when the image data is A / D converted from the image signal at the timing of a clock having a half cycle of the cycle of outputting the image signal by the charge-coupled device, the image data becomes 1 The difference between the image data delayed by one clock and the image data delayed by one clock is calculated. Then, the difference is output every other one. Therefore, it is possible to reduce a noise component included in the image signal output from the charge-coupled device.

  According to the present invention, since the imaging device in which the substrate and the holder are integrated is housed in the housing, the size, thickness, weight, and cost can be reduced.

  According to the information processing method according to the present invention, the image signal output from the imaging device of the imaging adapter device is fetched and processed, so that the image signal can be easily transmitted at any place. Become.

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

[First embodiment]
FIG. 1 is a perspective view showing a configuration of a first embodiment of an imaging apparatus to which the present invention is applied. This imaging apparatus is configured such that a holder 2 is mounted (fitted) on a substrate 1 so that they are integrated. As will be described later with reference to FIG. 3, the substrate 1 is a photoelectric conversion element that photoelectrically converts at least light formed by an imaging lens 4 provided in a holder 2 and outputs an image signal. For example, a CCD bare chip 12 is mounted. Further, the holder 2 is provided with one imaging lens 4 for forming an image of light, and its exterior is provided with a diaphragm that blocks such peripheral light so that the peripheral light does not enter the imaging lens 4. The package 2A has an effect and further blocks external light. The package 2A is provided with a circular hole (aperture) 3 for allowing light from a subject to enter the imaging lens 4. In this embodiment, the hole 3 is provided substantially at the center of the upper part of the package 2A and functions as a fixed iris.

  Next, FIG. 2 is a plan view of the imaging device of FIG. 1, and FIG. 3 is a cross-sectional view of an A-A ′ portion (portion shown by a cross-sectional line in FIG. 2) in FIG. As described above, the CCD bare chip 12 is mounted on the substrate 1, a driver 13 for driving the CCD bare chip 12, an A / D converter 14 for A / D converting an output of the CCD bare chip 12, and others. Necessary chips are mounted (details will be described later with reference to FIG. 18). The CCD bare chip 12 is mounted at a position facing the hole 3 provided in the holder 2 when the holder 2 is mounted on the substrate 1. However, if the mounting position of the CCD bare chip 12 is restricted due to the design of the substrate 1, the mounting position of the CCD bare chip 12 is determined first, and then the hole 3 is provided at a position facing the CCD bare chip 12. You can do so.

  Further, on the side surface of the substrate 1, for outputting a signal to the outside and inputting a signal from the outside (for example, an image signal output from the CCD bare chip 12 and subjected to predetermined processing is taken out, or For supplying power to each chip mounted on the chip). In FIG. 1, the illustration of the leads 5 is omitted.

  Each chip mounted on the substrate 1 is connected by a connection line as needed. In FIG. 3, only the connection lines 13A drawn from the driver 13 are shown, and connection lines drawn from other chips are omitted because the drawing is complicated.

  FIG. 4 shows a configuration example of the CCD bare chip 12. In this embodiment, a CCD bare chip 12 is formed on a CCD element (charge coupled element) 12A for outputting an electric signal corresponding to input light, and is formed on the CCD element 12A. And a color filter 12B that allows light of a predetermined wavelength to pass therethrough. However, the color filter 12B may be omitted.

  As is clear from a comparison between the CCD bare chip 12 shown in FIG. 4 and the CCD image pickup device 403 shown in FIG. 56, the CCD bare chip 12 shown in FIG. The configuration is such that the package 403B made of plastic is omitted. Therefore, the size can be smaller than that of the CCD image sensor 403 shown in FIG.

  The imaging lens 4 forms a lens unit 10 together with the leg unit 11. Here, FIG. 5 is a perspective view illustrating a detailed configuration of the lens unit 10. The lens unit 10 is made of, for example, a transparent plastic (for example, PMMA) as a transparent material, and has a so-called table shape in which four legs are provided on a parallel flat plate. That is, an imaging lens 4 as a single lens is formed at the central portion of the parallel plate, and further, at four corners of the parallel plate, extends in a direction parallel to the optical axis of the imaging lens 4, for example. Four legs 11 having a prismatic shape having a rectangular horizontal cross section are provided. A lower portion of each of the four legs 11 and a corner portion facing the optical axis of the imaging lens 4 is hollowed out in a prismatic shape, thereby forming a notch 11A. Each of the four legs 11 is provided such that two of the four side surfaces (corner portions formed by the two side surfaces) face the optical axis of the imaging lens 4. I have.

  The shape of the CCD bare chip 12 as viewed from the upper surface (imaging surface) thereof is, for example, a rectangular chip, and each of the four notches 11 </ b> A is formed so as to be accurately fitted to the four corners of the CCD bare chip 12. I have.

  The lens unit 10 is formed by molding a plastic, for example, by molding (accordingly, the imaging lens 4 is a plastic molded single lens), whereby the lens unit with respect to the principal point of the imaging lens 4 is formed. The relative accuracy of the dimensions of each part of 10 is sufficiently high.

  As shown in FIGS. 2 and 3, the lens unit 10 configured as described above is connected to a position corresponding to the hole 3 inside the lid-shaped package 2 </ b> A constituting the exterior of the holder 2. The image lens 4 is fitted so that the optical axis passes through the center of the hole 3. The four legs 11 of the lens unit 10 are in direct contact with the CCD bare chip 12 by fitting the notches 11A into the four corners of the CCD bare chip 12.

  The package 2A constituting the exterior of the holder 2 is made of, for example, a polycarbonate resin or the like as a light-shielding material, and is also bonded to the substrate 1 by a light-shielding filler (adhesive) 20. And the holder 2 are integrated.

  FIG. 6 is an enlarged view of a cross section of a portion where the leg 11 and the CCD bare chip 12 are in contact (an enlarged view of a portion Z surrounded by a dotted line in FIG. 3). As shown in the figure, the lower end of the leg 11 is slightly floating from the substrate 1, and the bottom and side surfaces of the notch 11 A are the light receiving surface of the CCD bare chip 12 (the portion indicated by S 1 in the figure) and its side surface. (The portion indicated by S2 in the figure) is in direct contact with a certain degree of pressure (therefore, the leg 11 is brought into contact with the CCD bare chip 12 as it were). This pressure is generated when the holder 2 is fitted to the substrate 1 and then the substrate 1 and the holder 2 are bonded and sealed by filling the filler 20 while applying a predetermined pressure. ing.

  The dimensions of the portion of the holder 2 to be fitted to the substrate 1 are slightly larger than the outer shape of the substrate 1. Therefore, the substrate 1 and the holder 2 are required to have the accuracy of bringing the leg 11 into contact with the CCD bare chip 12. Glued in a preferred form.

  As described above, at least the substrate 1 on which the CCD bare chip 12 is mounted and the holder 2 of the exterior (package 2A) having the aperture effect and provided with the imaging lens 4 are integrated, so that the imaging device can be used. For example, at the time of application to a video conference system or the like, optical adjustment between the imaging lens 4 and the CCD bare chip 12 is not required, so that the assembling and handling thereof are facilitated. As a result, it is possible to reduce the manufacturing cost of a device using such an imaging device.

  Further, as described above, the relative accuracy of the dimensions of each part of the lens unit 10 with respect to the principal point of the imaging lens 4 is sufficiently increased, and the legs 11 (notches 11A) of the lens unit 10 are provided with a CCD bare chip. Since the imaging lens 4 is directly abutted against the light receiving surface of the CCD 12, the imaging lens 4 can be adjusted without any special adjustment so that its principal point satisfies a predetermined positional relationship with the light receiving surface of the CCD bare chip 12. Well placed. That is, the imaging lens 4 can be mounted at low cost and with high accuracy. Further, in this case, since an adjusting mechanism for accurately mounting the imaging lens 4 is not required, the size and weight of the imaging device can be reduced.

  Note that a projection 11Aa may be formed on the notch 11A surface of the leg portion 11 that presses the imaging surface of the CCD bare chip 12, and the CCD bare chip 12 may be pressed by the projection 11Aa. By making the projection 11Aa hemispherical or cylindrical, the contact between the CCD bare chip 12 and the leg 11 is theoretically made at a point or a line. Irrespective of the precision of the surface, the CCD bare chip 12 can be reliably pressed.

  Alternatively, as shown in FIG. 8, a tapered surface 11Ab may be formed in the notch 11A of the leg 11, and the edge of the upper end of the CCD bare chip 12 may be pressed by the tapered surface 11Ab. In this manner, the CCD bare chip 12 can be reliably pressed regardless of the variation in the shape of the CCD bare chip 12.

  Next, the optical characteristics of the imaging lens 4 and the dimensions (length) of the legs 11 will be described with reference to FIGS. As shown in FIG. 9A, the focus position (imaging plane) f1 of the imaging lens 4 is curved as shown by a broken line. Then, the light receiving surface (imaging surface) of the CCD bare chip 12 is arranged at a position on an ideal image surface (flat surface that is not curved) f2 that is in contact with the imaging surface f1 on the optical axis of the imaging lens 4 ( The length of the leg 11 is set so as to have such an arrangement relationship).

  However, if it is left as it is, focusing is performed in the vicinity of the center of the imaging plane (near the point where the imaging plane f1 and the ideal image plane f2 are in contact with each other), but as the distance from the center of the imaging plane increases (in FIG. The greater the distance from the point where f1 and the ideal image plane f2 are in contact with each other in the vertical direction), the larger the defocus amount of the imaging plane f1 from the focus position imaging plane (ideal image plane f2). In other words, the image at the center on the imaging surface is a clear image in focus, whereas the image at the periphery is a so-called out-of-focus image.

  Therefore, the imaging lens 4 is designed so that spherical aberration occurs on the optical axis of the imaging lens 4 so that a uniform defocus amount is obtained on the entire imaging surface. As a result, as shown in FIG. 9A, the light that should be focused near the contact point between the imaging surface f1 and the ideal image surface f2 originally (if no spherical aberration occurs) is shifted from its position by, for example, Focusing at a farther position. As a result, a so-called slightly out-of-focus state also occurs at the center of the imaging surface, and an image in a substantially uniform focus state is obtained over the entire imaging surface.

  That is, as a result, the half width of the response of the imaging lens 4 to the point light source is changed to the central portion (FIG. 9B) on the light receiving surface of the CCD bare chip 12 as shown in FIGS. 9B and 9D. 9) and also in the peripheral portion (FIG. 9 (D)), and is set to be larger than the pixel pitch of the CCD bare chip 12.

  Here, FIG. 9 (A) or FIG. 9 (C) shows a state where parallel rays are converging on the central part or peripheral part of the CCD bare chip 12, respectively, and FIG. 9 (B) or FIG. ) Indicates the light intensity (response to a point light source at infinity) on the light receiving surface of the CCD bare chip 12 in the case shown in FIG. 9A or 9C. In this embodiment, the half-value width w1 or w2 of the point light source response at the central portion or the peripheral portion of the CCD bare chip 12 is almost twice the pixel pitch of the CCD bare chip 12 (preferably, for example, 1.8 to 3 times). (Approximately twice) (the same applies to other positions on the light receiving surface of the CCD bare chip 12). As a result, as the CCD bare chip 12, an element having a low pixel count of about 170,000 pixels having 360 pixels in the horizontal direction and 480 pixels in the vertical direction can be used.

  As described above, by setting the half-value width of the point light source response to twice the pixel pitch of the CCD bare chip 12, the spatial frequency response characteristic of the imaging lens 4 is reduced to the Nyquist limit of the CCD bare chip 12, as shown in FIG. The characteristic is such that incident components having a spatial frequency fn or higher are sufficiently suppressed. Therefore, conventionally, as described with reference to FIG. 52, an optical LPF 112 for reducing aliasing distortion was required. However, the imaging apparatus of FIG. 1 reduces aliasing distortion without providing such an optical element. can do. As a result, the size, weight, and cost of the device can be reduced.

  In FIG. 9, light near the optical axis is focused in a direction away from the imaging lens 4 by a predetermined distance from the imaging surface f1 (ideal image surface f2) of the imaging lens 4. However, conversely, it is also possible to focus in a direction approaching the imaging lens 4.

  In the present embodiment, the imaging lens 4 has a short focal length (for example, about 4 mm), and has a small hole 3 that functions as a diaphragm (for example, the diameter is about 1.2 mm). It has been. As a result, even if the depth of field becomes deeper and the distance to the subject changes, the degree of blurring becomes smaller. In addition, this imaging device does not need to be provided with a focusing mechanism such as a so-called auto-focusing mechanism. In this regard, the size, weight, and cost of the device are reduced. When the image pickup apparatus is used for telephoto, a lens having a long focal length may be used as the imaging lens 4 and the hole 3 may be made smaller.

  FIG. 11 summarizes the relationship between the imaging plane and the imaging plane. That is, the imaging surface f1 of the imaging lens 4 is curved with respect to the ideal image surface f2. In the above embodiment, the imaging surface 203 of the CCD bare chip 12 is arranged on the ideal image surface f2. Will be.

  However, in this case, the defocus amount in the peripheral portion is larger than that in the central portion of the imaging surface 203. Therefore, as described above, spherical aberration is generated in the central portion, so that The entire image is made to be an image with uniform focus.

  However, in the case of this embodiment, the defocus amount in the peripheral portion tends to be too large as compared with the central portion.

  Therefore, for example, as shown in FIG. 12, the imaging surface 203 of the CCD bare chip 12 may be arranged substantially at the center of the imaging surface f1 of the imaging lens 4 (the center in the horizontal direction in FIG. 12). By doing so, the defocus amounts in the peripheral portion and the central portion are opposite in direction but their absolute values are substantially the same. However, in this case, the focus state near the point A where the imaging plane 203 and the imaging plane f1 intersect is better than the focus state at other positions. Therefore, the imaging lens 4 can be designed so that a large amount of aberration occurs near the point A. In this way, it is possible to obtain an image in a substantially uniform focus state on the entire imaging surface 203.

  Next, conditions for obtaining a uniform image on the entire imaging surface 203 will be described in more detail with reference to the example shown in FIG.

  Now, as shown in FIG. 13, the horizontal length (long side length) Lh of the effective pixel area of the CCD bare chip 12 is 2.0 mm, and the vertical length (short side length) Lv is If it is 1.5 mm, the length of the diagonal length Ld is about 2.5 mm.

Assuming that the focal length f of the imaging lens 4 is 4.0 mm, the angle of view in the long side direction is obtained as approximately 28 degrees from the following equation.
Angle of view in the long side direction = 2 × atan (2.0 / (2 × 4.0))

  Here, atan means an arctangent function.

  The F-number (= f / D) defined by the focal length f of the imaging lens 4 and the pupil diameter D is 2.8.

The radius R of the curved image plane f1 is equal to the reciprocal of the Petzval sum P. That is, the Petzval sum P is represented by the following equation. Here, n represents the refractive index of the imaging lens 4.
P = Σ1 / (nf)

In this case, since there is only one image forming lens 4, the radius R of the image plane 201 according to the present embodiment can be obtained by the following equation, where the refractive index n is 1.5.
R = 1 / P = n × f = 1.5 × 4.0 = 6.0

Now, as shown in FIG. 13, it is considered to make the range from the center of the effective pixel area to 70% of 1/2 of the diagonal length Ld uniform. The position Lm at 70% of 1/2 of the diagonal length Ld from this center can be obtained from the following equation.
Lm = 0.7 × Ld / 2 = 0.375 × Lh = 0.875 mm

As shown in FIG. 14, the center of the imaging plane f1 is O, the intersection of the optical axis of the imaging lens 4 and the ideal image plane f2 is S, and the ideal image plane f2 is separated from the point S by a distance Lm. When the point is Q, the intersection of the image plane f1 and the line 205 located at a distance Zm from the ideal image plane f2 toward the imaging lens 4 is T, and the intersection of the line 205 and the optical axis is U , Points T, O, and U are approximated by approximately atan (Lm / R). Therefore, the distance between the points O and U is obtained by the following equation, where R is the radius of the imaging plane f1 (the distance between the points O and T = the distance between the points O and S).
R × cos {atan (Lm / R)}

Therefore, the amount of curvature Zm of the imaging plane f1 from the ideal image plane f2 at the position of the point Q where the distance from the point S on the optical axis on the ideal image plane f2 is Lm (the image height is Lm). Can be obtained from the following equation, assuming that R = 0.6 mm and Lm = 0.875 mm.
Zm = R × (1-cos {atan (Lm / R)}) = 0.0628 mm

Now, assuming that the imaging plane 203 is arranged at a position of Zm / 2 from the ideal image plane f2 to the imaging lens 4 side, in the vicinity of the end of the screen (the position of the image height Lm) and the center of the screen. , Zm / 2 defocus occurs. The diameter α of the circle of confusion generated by this defocus is
F = f / D = (Zm / 2) / α
Can be obtained from the following equation.
α = (Zm / 2) /F=0.0314/Fmm

Further, the MTF based on the circular aperture can be obtained from the following equation.
M (ω) = [J1 {πα (k / Lh)}] / {πα (k / Lh)}

  Here, J1 represents a first-order Bessel function of the first kind, and k / Lh represents a spatial frequency in the horizontal direction. Therefore, k corresponds to the number dividing the length Lh in the horizontal direction. Since the vertical resolution characteristics are determined by the scanning lines of the television system, only the horizontal direction will be considered here.

Since the value when the first-order Bessel function J1 of the first kind becomes 0 first is 3.83, the following equation is established.
πα (k / Lh) = 3.83

Therefore, when the trap point fn (= k / Lh) of the MTF shown in FIG. 10 is obtained from the above equation, the following is obtained.
(K / Lh) = 3.83 / (πα) = 38.8F

Therefore, k can be obtained as follows.
k = 38.8 × F × Lh = 38.8 × 2 × F = 77.6F

Therefore, the minimum number of pixels G required to secure the spatial frequency can be obtained from the following equation according to the sampling theorem.
G = 2k = 2 × 77.6F = 155F

In the above calculation, the refractive index n of the imaging lens 4 is obtained as 1.5, but if a higher value (for example, 1.9) is used, the following equation is obtained.
G = 2k = 200F

  That is, the condition for obtaining a uniform image is that the effective pixel pitch of the CCD bare chip 12 is larger than 1 / (200F) of the long side of the effective area. This means that the number of effective pixels in the horizontal direction is smaller than 200F.

  In FIG. 14, the diameter α of the circle of confusion can be obtained as the distance between the point at which the line connecting the end of the opening of the imaging lens 4 and the point T intersects the imaging plane 203.

Therefore, as schematically shown in FIG. 15, the pitch P _P of the imaging surface of the pixel 211 of the CCD bare chip 12 shown in FIG. 3 is formed so as to satisfy the above conditions.

Next, a description will be given of the condition of the focal length f for imaging an object at a distance from the closest distance S to infinity (∞) by using one imaging lens 4 so that defocus is reduced as much as possible. . Now, as shown in FIG. 16, assuming that the amount of deviation between the image formation position of the object at infinity by the imaging lens 4 and the image formation position of the object at a close distance S by the image formation lens 4 is g, The following equation holds from the formula:
g × (S−f) = f ²

By rearranging the above equation using the fact that the distance S is sufficiently larger than the focal length f, the following equation is obtained.
^{g = f 2 / (S-} f) = f 2 / S

  In order to reduce the amount of defocus as a whole in the range of the deviation amount g, the imaging surface 203 of the CCD bare chip 12 is set at the middle point (position of g / 2) of the deviation amount g. Good.

As in the case of FIG. 13, when the long side of the screen of the image sensor is Lh and the radius of curvature of field is R (= n × f), the curvature Z of the image plane at the image height L is given by the following equation. You can ask.
Z = R × (1−R ² −L ² ) ^1/2
Here, since L ² / R ² is sufficiently smaller than 1, the above equation can be rearranged as follows.
Z = R × (1- (1-L ² / (2 × R ² )))
= L ² / (2 × R) = L ² / (2 × n × f)

Since there is no correlation between g / 2 and Z, the square of the total defocus amount D can be expressed as the sum of the squares as shown in the following equation.
D ² = (g / 2) ² + Z ^{2
= (F 2/2 × S} ) 2 + (L 2 / (2 × n × f)) 2
= (F ^4/4 × S ² ) + L ⁴ / (4 × n ² × f ² )

If the equation obtained by differentiating D ² with f is set to 0 in order to find f that gives the minimum value of D ² obtained by the above equation, the following equation is obtained.
f ³ / S ² −L ⁴ / (2 × n ² × f ³ ) = 0

By solving this equation, the following equation is obtained.
f = ((S ² × L ⁴ ) / (2 × n ² )) ^(1/6)

  In other words, the focal length f given by the above equation may be obtained by the imaging lens 4, but it is possible to have a certain width without setting it strictly to the value given by the above equation. .

That is, in general, the important part of the image is from the center of the screen to 70% of half the diagonal length of the screen. May be set to 0.35 to 0.5 times the length of half the diagonal length. Assuming that the aspect ratio of the screen is 4: 3, the length of the half of the diagonal length is (5/8) × Lh, so that the image height L may be set in the following range. .
0.35 x (5/8) x Lh
= 0.219 Lh <L <0.5 x (5/8) x Lh
= 0.312Lh

In consideration of application to a video conference or the like, the above-described short distance S may be 200 mm to 300 mm. Further, the refractive index n of the imaging lens 4 is
n = 1.4 to 1.9
It is. By substituting these conditions into the above formula for the focal length f and rearranging, the following formula is obtained.
1.53 × (Lh ^(2/3) ) <f <2.46 × Lh ^(2/3)

  That is, if the focal length f of one imaging lens 4 is set within the range defined by the above expression, it is possible to capture an image of a subject existing at infinity from the closest distance S without blurring.

FIG. 17 shows an example of calculation of the square root of the focal length f (horizontal axis) and the square of the total defocus amount D ((D ² ) ^1/2 ) (vertical axis). In this case, L = 0.63 mm, S = 200 mm, and n = 1.5.

  That is, in this example, when the focal length f is set to about 4 mm, the amount of defocus is the smallest.

  Next, a method of manufacturing the imaging device shown in FIGS. 1 and 3 will be described with reference to FIGS. First, as shown in FIG. 18, the CCD bare chip 12 and, if necessary, other chips are mounted on the substrate 1 and are electrically connected as necessary. In this embodiment, a driver 13, an A / D converter 14, a timing generator 15, a memory (two-port memory) 16, and a signal processing circuit 17 are mounted as other chips. Further, necessary leads 5 are provided on the substrate 1, and electrical connection with a chip mounted on the substrate 1 is performed as necessary.

  On the other hand, as shown in FIG. 19, using a light-shielding material or a transparent material, the package 2A or the lens portion 10 provided with the hole 3 is molded respectively, and the lens portion 10 is provided in the hole 3 portion of the package 2A. Are fitted together to manufacture the holder 2.

  Then, the substrate 1 and the holder 2 are integrated by filling a filler 20 as shown in FIG. 3 in a state where the leg 11 of the lens unit 10 is abutted against the CCD bare chip 12.

  As described above, when the substrate 1 and the holder 2 are integrated, no special adjustment is required, so that the imaging device can be manufactured easily and at low cost.

  In the above case, the holder 2 is manufactured by separately molding the package 2A or the lens unit 10 and then integrating them, but in addition, as shown in FIG. The holder 2 can be manufactured by simultaneously molding the package 2A and the lens unit 10 using a light-shielding material and a transparent material. Further, in this case, as shown in FIG. 21, the legs 11 of the lens unit 10 can be configured using a light-shielding material instead of a transparent material. In this case, it is possible to prevent the reflection of light on the legs 11, and as a result, it is possible to reduce flare.

  FIG. 22 illustrates an example of an electrical configuration of a video camera to which the imaging device in FIG. 1 is applied. Light from the subject enters the imaging lens 4 through the hole 3, and the imaging lens 4 forms the image on the light receiving surface of the CCD bare chip 12. The CCD bare chip 12 operates according to various timing signals yv, yh, and ys supplied from the driver 13, performs photoelectric conversion of light formed by the imaging lens 4, and obtains an image obtained as a result. The signal is output to a cds processing circuit (correlated double sampling processing circuit) 21. The driver 13 converts the levels of the timing signals xv, xh, xs supplied from the timing generator 15 for driving the CCD bare chip 12 and converts the impedance to convert the timing signals yv, yh, xh. ys. The CCD bare chip 12 is driven by supplying it to the CCD bare chip 12.

  The A / D converter 14 samples the image signal from the cds processing circuit 21 according to the sampling clock pa supplied from the timing generator 15, and converts the image signal into digital image data to the memory 16 and the accumulator 22. The output has been made. The A / D converter 14 is configured to determine a bit to be assigned to a sample value based on a reference voltage vref supplied from the outside. The timing generator 15 generates various timing signals based on a clock supplied from an external clock generation circuit 31. That is, the timing generator 15 discharges the timing signal xv or xh for transferring the charge generated in the CCD bare chip 12 in the vertical or horizontal direction, and the charge generated in the CCD bare chip 12 (substrate of the CCD bare chip 12). (A shutter pulse) xs, a timing signal sh for operating the cds processing circuit 21, a sampling clock pa for giving a sampling timing in the A / D converter 14, and a memory 16. A timing signal w for giving the timing of writing the image data is generated.

  The memory 16 is, for example, a two-port memory capable of simultaneously reading and writing data, and stores image data from the A / D converter 14 in accordance with a timing signal w supplied from the timing generator 15. ing. The image data stored in the memory 16 is read by an external MPU (microprocessor unit) 32. When the MPU 32 reads image data from the memory 16, the MPU 32 gives a predetermined address to the memory 16 via the address bus adrs, and the image data stored at that address is read on the data bus data. Is output to the MPU 32, and this is performed by the MPU 32 taking in the data.

  The cds processing circuit 21 operates according to the timing signal sh supplied from the timing generator 15, and performs so-called correlative double sampling and other processing on the image signal from the CCD bare chip 12. Is performed, thereby reducing (or removing) noise components included in the image signal, and outputting the result to the A / D converter 14.

  The accumulator 22 calculates the integrated value of the image data output from the A / D converter 14 corresponding to the main part (for example, the center part) of the light receiving surface of the CCD bare chip 12 and outputs it to the timing generator 15. It has been made to be. The timing generator 15 controls the timing signal for discharging the charge generated in the CCD bare chip 12, that is, the timing of the shutter pulse xs, so that the integrated value supplied from the accumulator 22 does not largely deviate from a predetermined specified value. Thus, the iris is adjusted electronically. That is, if the integrated value becomes large, the exposure time (charge accumulation time) is shortened, and if the integrated value becomes small, the exposure time is lengthened. The accumulator 22 is reset at a field cycle (a frame cycle in some cases). Therefore, the accumulator 22 outputs the integrated value of the image data for each field (or one frame).

  The clock generation circuit 31 is connected to the timing generator 15 via the lead 5, generates a clock for operating the video camera, and supplies the clock to the timing generator 15. The MPU 32 reads image data from the imaging device (memory 16) via the address bus adrs or data bus data and the lead 5, and performs predetermined signal processing.

  Further, a voltage Vd serving as a power supply of each chip, a predetermined reference voltage gnd serving as a ground, and a voltage Vh for driving the CCD bare chip 12 are supplied from the outside via the leads 5. .

  Note that the cds processing circuit 21 and the accumulator 22 correspond to the signal processing circuit 17 in FIG.

  Next, the operation will be described. Light from a subject enters an imaging lens 4 through a hole 3 functioning as a fixed stop, and this light is imaged on a light receiving surface of a CCD bare chip 12 by the imaging lens 4.

  Here, FIG. 23 illustrates a state in which light L out of the imaging target, which is emitted from the imaging lens 4, is reflected by the front surface of the leg 11. As described above, the leg 11 has two side surfaces facing the optical axis of the imaging lens 4, and has a rectangular cross section. Is a right angle. Therefore, as shown in the figure, when the light L outside the imaging target is reflected on the side surface of the leg 11, the reflected light does not reach the light receiving surface of the CCD bare chip 12. Therefore, there is almost no increase in flare due to the provision of the legs 11.

  Note that the angle a may be an acute angle other than a right angle. However, it is not preferable to set the angle a to an obtuse angle because the light reflected on the front surface of the leg portion 11 gradually enters the CCD bare chip 12 side in FIG.

  Further, for example, a light-shielding paint may be applied to the leg portion 11 so as to prevent light incident thereon from reaching the CCD bare chip 12. Further, the cross-sectional shape of the leg 11 may be a quadrangle other than a rectangle, a triangle, a pentagon, or the like. However, in order to prevent an increase in flare, the angle of a corner formed by at least one adjacent side surface of the side surfaces of the leg portion 11 is set to a right angle or an acute angle, and the angle portion is formed by the imaging lens 4. It is necessary to face the optical axis.

  Returning to FIG. 22, in the CCD bare chip 12, the light received there is photoelectrically converted, and an image signal corresponding to the light is output to the cds processing circuit 21 according to a timing signal from the driver 13. In the cds processing circuit 21, the image signal from the CCD bare chip 12 is subjected to a correlated double sampling process and output to the A / D converter 14. The A / D converter 14 samples the image signal from the cds processing circuit 21, converts the image signal into digital image data, and supplies the digital image data to the accumulator 22. The accumulator 22 integrates the above-mentioned predetermined data among the image data from the A / D converter 14, and outputs the integrated value to the timing generator 15. The timing generator 15 generates various timing signals based on the clock from the clock generation circuit 31. When the integrated value is supplied from the accumulator 22, the integrated value does not largely deviate from a predetermined specified value. Next, the generation timing of the shutter pulse xs is changed.

  The image data output from the A / D converter 14 is also supplied to and stored in the memory 16 in addition to the accumulator 22. In the MPU 32, the image data is read from the memory 16 when necessary, and a predetermined process is performed.

  One package as an imaging device includes a CCD bare chip 12 that performs photoelectric conversion and outputs an image signal, an A / D converter 14 that A / D converts an output of the CCD bare chip 12, and an output of the A / D converter 14. Is provided, and when the imaging device is viewed from the MPU 32, the imaging device is equivalent to the memory, and therefore, there is no need to be aware of the synchronous relationship between the imaging device and its external blocks. As a result, when the imaging device is applied to the above-described video camera or another device, it can be easily incorporated and handled.

  In addition, a camera circuit such as an NTSC encoder may be provided instead of the memory 16 to convert image data into an NTSC video signal and output the video signal.

  In this embodiment, a CCD bare chip is used as the photoelectric conversion element for photoelectrically converting the light from the imaging lens 4. However, as the photoelectric conversion element, for example, a capacitor such as a CMOS type image pickup element may be used. It is also possible to use a bare chip of a destructive read-out type image sensor for reading out the charges charged in the device as image signals. Further, as the photoelectric conversion element, a photoelectric conversion element other than the destructive readout imaging element can be used. When a photoelectric conversion element other than the CCD is used, the cds processing circuit 21 does not need to be provided.

  Further, in the present embodiment, the memory 16 is a two-port memory. However, as the memory 16, a normal memory other than such a two-port memory can be used. However, when the memory 16 is not a two-port memory, a circuit for adjusting read of image data by the CPU 32 and writing of image data by the A / D converter 14 is required.

  Furthermore, in the present embodiment, each of the four legs 11 of the lens unit 10 is brought into direct contact with the four corners of the CCD bare chip 12. For example, it is possible to provide so as to be in contact with each of the sides (portions marked with ▲ in FIG. 2). However, in this case, the reflected light reflected by the legs 11 is incident on the CCD bare chip 12 to cause a flare, and it is difficult to pull out the connection line from the CCD bare chip 12. As described above, it is preferable to provide the CCD bare chip 12 so as to be in contact with the four corners.

  Alternatively, as shown in FIG. 24, two legs 11 of the lens unit 10 are provided, and two opposing sides of the sides marked with ▲ in FIG. 2 are held by the notches 11A. It is also possible to do so. Further, also in this case, the protrusion 11Aa or the tapered surface 11Ab shown in FIG. 7 or FIG. 8 can be provided.

  In the embodiment of FIG. 3, the lens unit 10 is integrated with the package 2A (holder 2). However, as shown in FIG. 25, a gap may be provided between the two. is there. In this case, the lower end of the leg 11 is attached to the substrate 1 with the filler 20. In this way, when pressure is applied to the holder 2 from the outside, it is less likely to be directly transmitted to the lens unit 10, and damage to the lens unit 10 can be suppressed. Become. In the case of this embodiment, the position of the aperture formed by the hole 3 is separated from the imaging lens 4, but the effect of the aperture is not so sensitive, so there is almost no problem in practical use.

  In general, synthetic resins have a coefficient of thermal expansion about 10 times larger than glass and a change in refractive index with temperature about 100 times larger than glass. As a result, when the imaging lens 4 is formed of a synthetic resin, when the temperature changes, the focal length changes, and it becomes difficult to use the imaging lens 4 over a wide temperature change without providing an adjusting mechanism. Therefore, in this embodiment, the adjusting mechanism is substantially provided as follows, for example.

That is, as shown in FIG. 26, when the temperature rises, the length L11 of the leg ₁₁ increases. In addition, the following equation substantially holds between the refractive index n of the convex lens and the focal length f.
f = K / (2 (n-1))
Here, K is a coefficient relating to the curvature of the lens spherical surface.

  Therefore, when the temperature increases, the focal length f of the imaging lens 4 shown in FIG. 26 changes.

Now, it is assumed that a change in the refractive index with respect to a change in the unit temperature is a (/ degree), and a coefficient of linear expansion of the leg 11 is b (/ degree). Usually, a of the resin lens is a negative value, its order is 10 ^{-5 to} 10 ^-4 , and b is a positive value, and its order is 10 ^{-5 to} 10 ^-4 .

Now, assuming that a change in the focus position when the temperature rises by T (degrees) at normal temperature is Δf, the change in the focus position Δf can be expressed as follows.
Δf = K / (2 (n−1 + a × T)) − R / (2 (n−1))
= −a × T × K / (2 (n−1 + a × T) × (n−1))
= −a × T × f / (n−1 + a × T)

However,
R = 2 × (n−1) × f
It is.

Usually, since n-1≫a × T holds, the above equation can be expressed as follows.
Δf = −a × T × f / (n−1)

Further, when the temperature rises by T, the increase amount ΔL of the length L ₁₁ of the leg portion 11 can be expressed by the following equation.
ΔL = b × T × L ₁₁

Therefore, the actual movement amount Δh of the focal length plane is as follows.
Δh = Δf−ΔL

Therefore, the design is performed so that Δh falls within the depth of focus ΔZ of the imaging lens 4, that is, the following equation: | −a × f / (n−1) −b × L ₁₁ | <(ΔZ / T)
Is designed so as to satisfy the following condition, it is possible to position the focus position f1 on the light receiving surface of the CCD bare chip 12 even if the temperature changes.

  Further, in the above embodiment, the spatial frequency of the incident light image is limited by using the aberration of the lens, and the aliasing distortion generated on the CCD bare chip 12 is reduced. However, depending on the application of the camera, it is required to sufficiently suppress color moiré generated in a single-chip color camera. In this case, it is necessary to sharply suppress only a specific spatial frequency. However, it is difficult to sharply suppress only a specific spatial frequency by the spatial frequency limiting method as in the above-described embodiment.

  Therefore, for example, as shown in FIG. 27, the image forming lens 4 is divided into two by a horizontal plane passing through the center thereof to form image forming lenses 4A and 4B. On the other hand, a lens having a configuration in which the discontinuous surface 4 </ b> C is formed by rotating horizontally by the angle θ can be used. FIG. 28 shows the imaging lens 4 as viewed from above.

In this case, the position where the light from the subject passes through the upper imaging lens 4A and then forms an image on the CCD bare chip 12 and the position where the light passes through the lower imaging lens 4B and forms an image on the CCD bare chip 12 are as follows. , In the horizontal direction by a distance Q. That is, at this time, the following equation is established.
θ = 2 × atan (Q / 2f)

  As a result, the MTF by the imaging lenses 4A and 4B is as shown in FIG. 29, and has a characteristic that sharply decreases when the spatial frequency is 1 / (2Q).

  In order to obtain such characteristics, the direction of the discontinuous surface of the imaging lens 4 does not necessarily have to be horizontal, and as shown in FIG. 30, the vertical direction (FIG. 30A) or the oblique direction (FIG. 30B).

  Further, in the above embodiment, the leg 11 of the lens unit 10 is directly in contact with the CCD bare chip 12, but it may be in contact with the substrate 1. FIG. 31 shows an example in this case.

  That is, in the embodiment shown in FIG. 31, a concave portion 1A having a shape slightly larger than the CCD bare chip 12 is formed in the substrate 1. The CCD bare chip 12 is bonded to the concave portion 1A with a filler 20. The leg portion 11 of the lens portion 10 has a notch 11A fixed to a corner of the concave portion 1A of the substrate 1. The outer periphery of the leg 11 is adhered to the substrate 1 by the filler 20. Other configurations are the same as those in FIG.

  FIG. 32 shows a process for attaching the CCD bare chip 12 and the lens unit 10 to the substrate 1 in the embodiment of FIG.

  That is, first, as shown in FIG. 32A, the imaging surface of the CCD bare chip 12 is sucked by a jig 501 for gripping a suction-type IC chip. Then, as shown in FIG. 32 (B), the filler 20 is applied in advance to the concave portion 1A of the substrate 1, and as shown in FIG. 32 (C), the CCD bare chip 12 held by the jig 501 is removed. Die bonding is performed in the concave portion 1A of the substrate 1. At this time, the upper surface 1B of the substrate 1 comes into contact with the surface 501A of the jig 501, and the imaging surface of the CCD bare chip 12 is positioned at the same height as the upper surface 1B of the substrate 1.

  Next, as shown in FIG. 32D, the notch 11A of the lens unit 10 is engaged with a corner formed by forming the recess 1A of the substrate 1. Then, as shown in FIG. 32 (E), a filler 20 is filled between the outer periphery of the leg 11 and the upper surface of the substrate 1 and bonded.

  In this embodiment, since the CCD bare chip 12 is die-bonded in the recess 1A, the height of the imaging surface of the CCD bare chip 12 can be accurately determined. The mounting accuracy in ()) is slightly reduced. However, since the leg 11 of the lens unit 10 can be arranged at a position away from the imaging surface of the CCD bare chip 12, even if there is a bonding wire (not shown) of the CCD bare chip 12, this can be easily avoided. Thus, the lens unit 10 can be attached. Further, the influence of the poor reflection on the leg 11 can be reduced.

  Further, for example, the leg portion 11 of the lens portion 10 is a box-shaped leg portion having four sides surrounded as shown in FIG. 33 to prevent dust and the like from entering the inside. be able to. At this time, as shown in FIG. 33, a protrusion 11Aa can be provided on the bottom surface of the leg portion 11. Alternatively, for example, as shown in FIG. 34, a configuration in which two opposing legs are provided may be adopted. In this case, a cylindrical projection 11Aa can be formed on the bottom surface of the leg portion 11.

  FIG. 35 illustrates another configuration example of the imaging device illustrated in FIG. 22. That is, in this embodiment, the clock generation circuit 31 in FIG. 22 is housed inside the imaging device, and the camera processing circuit 511 is provided instead of the memory 16, and the output of the A / D converter 14 is Supplied. Then, the camera processing circuit 511 generates a luminance signal and a color difference signal, or R, G, and B signals. Further, an encoder may be incorporated therein so as to convert the data into video data in the NTSC format, for example. The output is supplied to the FIFO memory 512, stored once, and read at a predetermined timing. The data read from the FIFO memory 512 is input to a parallel / serial (P / S) converter 513, where the parallel data is converted into serial data. It is output as data of the opposite phase.

  On the other hand, the positive-phase and negative-phase data input from the input terminal 518 are input to the arbitration circuit 514 after the in-phase component is removed by the receiver 516. The arbitration circuit 514 controls the FIFO memory 512 in accordance with the input control data, writes data from the camera processing circuit 511, performs reading control at a predetermined timing, controls the driver 515, and controls the parallel serial communication. The data from the converter 513 is output.

  The driver 515 and the receiver 516 conform to the serial bus standard defined by IEEE1394. In addition, for example, it is also possible to conform to the USD.

  As described above, by configuring to output data serially and receive input, it is possible to prevent the imaging apparatus from becoming larger than in the case of inputting and outputting parallel data.

  The operation before the A / D converter 14 is the same as that in the case of FIG. 22, and the description thereof will be omitted.

[Second embodiment]
FIG. 36 is a perspective view showing the configuration of a second embodiment of the imaging apparatus to which the present invention has been applied. As in the image pickup apparatus of the first embodiment, this image pickup apparatus is also configured such that a holder (package) 52 is mounted (fitted) on a substrate 51 so that they are integrated. However, in order to further reduce the size, weight, and cost of the image pickup apparatus of the first embodiment, the holder 52 has one part for forming an image of light as a part thereof. An imaging lens 54 is formed on the upper portion (therefore, this holder 52 corresponds to the lens unit 10 in the first embodiment), and the light imaged by the imaging lens 54 is applied to the substrate 51. Only the CCD bare chip 12 (FIGS. 37 to 39) that performs photoelectric conversion and outputs an image signal is mounted. The holder 52 is made of a transparent material (for example, a transparent plastic (for example, PMMA) or the like), and its exterior part other than the imaging lens 54 is not so important for the CCD bare chip 12. A light-shielding light-shielding film 61 having an aperture effect of blocking such peripheral light is formed (coated) so that peripheral light does not enter. The CCD bare chip 12 is the same as that in the first embodiment.

  FIG. 37 is a plan view of the image pickup device of FIG. 36, and FIG. 38 or FIG. 39 is a cross-sectional view of a B-B ′ portion or a C-C ′ portion in FIG. 36, respectively. As described above, only the CCD bare chip 12 is mounted on the substrate 51. When the holder 52 is mounted on the substrate 51, the CCD bare chip 12 is mounted at a position facing the imaging lens 54 formed as a part of the holder 52.

  Further, similarly to the substrate 1, leads 55 for outputting signals to the outside and inputting signals from the outside are provided on the side surfaces of the substrate 51. 36, 38, and 39, the illustration of the lead 55 is omitted.

  From the CCD bare chip 12 mounted on the substrate 51, connection lines 12A for sending and receiving signals are drawn out, and each connection line 12A is connected to a predetermined lead 55.

  As described above, the holder 52 is made of a transparent material, and has a box-like shape having a rectangular cross section in the horizontal direction (in the case shown in FIG. 38, when it is turned upside down). An imaging lens 54 as a single lens is formed in a central portion of the bottom surface (upper portion of the imaging device), and an antireflection coating is applied to the inside including the imaging lens 54 except for the imaging lens 54. ing. That is, a light-shielding paint is applied to the holder 52, or a process similar thereto is performed, whereby the light-shielding film 61 is formed.

  Now, as shown in FIG. 37, the length of the side from which the connection line 12A of the CCD bare chip 12 is drawn out (the side in the vertical direction in FIG. 37) is the side without the lead-out line 12A (see FIG. 37). Horizontal side). Accordingly, of the two pairs of opposing legs 62, which are the four side surfaces of the holder 52, the distance between the legs 62 that oppose each other in the horizontal direction in FIG. 37 is short as shown in FIG. In FIG. 37, the distance between the legs 62 facing each other in the vertical direction is long as shown in FIG. The inner portion of one of the opposing legs 62 is hollowed out, thereby forming a notch 62A. The notch 62 </ b> A is fitted to two vertical sides of the CCD bare chip 12 with high accuracy.

  In this embodiment, the holder 52 is formed by molding a transparent plastic, for example (therefore, the imaging lens 54 is a plastic molded single lens like the imaging lens 4). Thus, the relative accuracy of the dimensions of each part of the holder 52 with respect to the principal point of the imaging lens 54 is sufficiently high.

  One of the opposite leg portions 62 of the holder 52 is brought into direct contact with the CCD bare chip 12 by fitting each of the notches 62A into two vertical sides of the CCD bare chip 12 in FIG. ing. The length of this one opposing leg 62 (vertical length in FIG. 38) is somewhat shorter than the length of the other opposing leg 62 (vertical length in FIG. 39). . This allows the notch 62A to directly contact the light receiving surface of the CCD bare chip 12 and its side surface with a certain pressure while the lower end of one of the opposed leg portions 62 (FIG. 38) is slightly floating from the substrate 51. (Therefore, one leg 62 (FIG. 38) is brought into contact with the CCD bare chip 12). This pressure is generated when the holder 52 is fitted to the substrate 51 and then the substrate 51 and the holder 52 are bonded and sealed by filling the filler 20 while applying a predetermined pressure. ing.

  The opposite leg 62 of the holder 52 (FIG. 39) is somewhat longer than the opposite leg 62 of the one (FIG. 38), but the notch 62A abuts against the light receiving surface of the CCD bare chip 12. The length is such that the lower portion does not contact the substrate 51 when it is pressed. Therefore, the substrate 51 and the holder 52 are adhered in such a manner that the accuracy of bringing one of the opposing legs 62 (FIG. 38) into contact with the CCD bare chip 12 is prioritized.

  Note that the optical characteristics of the imaging lens 54 and the dimensions (length) of the two legs (one (FIG. 38) opposing legs) 62 abutted on the CCD bare chip 12 will be described with reference to FIG. 11 or FIG. It is done in the same way as if you did.

  As described above, also in this embodiment, the substrate 51 on which the CCD bare chip 12 is mounted is integrated with the holder 52 on which the imaging lens 54 and the light-shielding film 61 having an aperture effect are formed. Incorporation and handling during application of the imaging device are facilitated, and manufacturing costs can be reduced.

  Further, the relative accuracy of the dimensions of each part of the holder 52 with respect to the principal point of the imaging lens 54 is sufficiently increased, and one of the opposing legs 62 (FIG. 38) receives light from the CCD bare chip 12. Since the imaging lens 54 is directly abutted on the surface, the imaging lens 54 can be accurately arranged without any special adjustment as in the case of the imaging lens 4 of the first embodiment. Thus, the size and weight of the imaging device can be reduced.

  Further, an imaging lens 54 is formed as a part of the holder 52, and only the CCD bare chip 12 is mounted on the substrate 51. Therefore, as compared with the case of the first embodiment, the imaging device Can be further reduced in size, weight, and cost.

  Further, as shown in FIG. 39, the distance between the other opposing legs 62 of the holder 52 is longer than the horizontal length of the CCD bare chip 12 in FIG. Routing can be easily performed.

  Next, a method of manufacturing the imaging device shown in FIGS. 36 to 39 will be described. First, the CCD bare chip 12 is mounted on the substrate 51, and the leads 55 are provided. If necessary, the connection lines 12A of the CCD bare chip 12 and the leads 55 are connected. On the other hand, a light-shielding film 61 is formed by molding a holder 52 having an imaging lens 54 and a leg 62 provided with a notch 62A using a transparent material. Then, the substrate 51 and the holder 52 are integrated by filling the filler 20 as shown in FIG. 38 and FIG. 39 in a state where one of the opposing legs 62 abuts against the CCD bare chip 12. .

  When the substrate 51 and the holder 52 are integrated, as in the case of the first embodiment, no special adjustment is required, so that the imaging device can be manufactured easily and at low cost.

  Also in this case, the holder 52 (imaging lens 54) can be molded using a transparent material and a light-shielding material. Thus, as shown in FIG. 40, the imaging lens 54 can be formed of a transparent material, and the legs 62 can be formed of a light-shielding material.

  Alternatively, as shown in FIG. 41, the imaging lens 54 is formed of a transparent material including the legs 62, and the outer sheet 91 and the inner sheet 92 are covered on the outer peripheral side and the inner peripheral side, respectively. The holder 52 may be formed. The outer sheet 91 and the inner sheet 92 are each formed of a light-shielding material and are formed corresponding to the outer peripheral side and the inner peripheral side of the imaging lens 54. Alternatively, instead of covering the outer sheet 91 and the inner sheet 92, the outer sheet 91 and the inner sheet 92 may be painted black.

  In addition, as shown in FIG. 42, for example, with the CCD bare chip 12 mounted on the substrate 51 and the imaging lens 54 mounted on the substrate 51, the outer circumferences of the substrate 51 and the imaging lens 54 are black resin. It is also possible to mold at 66.

  Further, this imaging apparatus drives by inputting the signal output from the driver 13 shown in FIG. 22 from the outside via the lead 55, and as a result, the image signal obtained via the lead 55 is also , Outside, signal processing is performed as necessary.

  Further, in the present embodiment, the CCD bare chip 12 is used as a photoelectric conversion element for photoelectrically converting the light from the imaging lens 54. However, as described in the first embodiment, as the photoelectric conversion element, For example, it is possible to use a destructive readout type image sensor or other devices.

  The size of the board 51 in the embodiment of FIG. 39 can be increased as shown in FIG. 43, and various components 67 can be arranged on the board 51.

  In addition, as shown in FIG. 44, the imaging lens may have a two-stage configuration of an imaging lens 54A (convex lens) and an imaging lens 54B (concave lens) as well as a one-stage configuration. Of course, a configuration having three or more stages is also possible.

[Third embodiment]
FIG. 45 shows a configuration example of a video camera incorporating the imaging device 100 to which the present invention is applied. In the figure, the same reference numerals are given to portions corresponding to the case in FIG. The imaging device 100 is configured similarly to the imaging device of the first embodiment or the second embodiment. However, the CCD bare chip 12 and the A / D converter 70 are mounted on the substrate 1 (or 51). In the present embodiment, it is assumed that the imaging device 100 has the same configuration as the imaging device of the first embodiment.

  The A / D converter 70 is a serial output type A / D converter. The A / D converter 70 converts an image signal output from the CCD bare chip 12 into its output cycle (after the image signal corresponding to a certain pixel is output, the next pixel). A / D conversion is performed at the timing of the sampling clock p1 having a period of の of the time until the image signal corresponding to (a) is output, and the resulting digital image data is output in the form of serial data. It has been done.

  Note that the A / D converter 70 determines a bit to be assigned to a sample value based on a reference voltage vref supplied from the outside.

  Further, as the A / D converter 70, it is also possible to use a parallel output type A / D converter that outputs image data obtained as a result of sampling in the form of parallel data (this case will be described later). The S / P converter 71 becomes unnecessary). However, when a parallel output type A / D converter is used as the A / D converter 70, it is necessary to provide leads 5 for the number of bits of image data to be output in the form of parallel data. When the / D converter 70 is a serial output type A / D converter, only one lead 5 is required to output image data. Therefore, if the A / D converter 70 is of a serial output type, the imaging device 100 can be made smaller.

  The S / P (serial / parallel) converter 71 converts serial image data output from the imaging device 100 (A / D converter 70) into parallel image data, and outputs a D-FF (delay flip-flop). 72 and a subtraction circuit 73. The D-FF 72 delays the image data from the S / P converter 71 by one clock according to a clock p2 having the same cycle as the sampling clock p1, and outputs the image data to the subtraction circuit 73. The subtraction circuit 73 calculates the difference between the image data from the S / P converter 71 and the output of the D-FF 72, and outputs the difference value to the D-FF 74. The D-FF 74 latches every other difference value output from the subtraction circuit 73 according to a clock p3 having a cycle twice as long as the clock p2 (the same cycle as the output cycle of the pixel), and outputs the camera signal. The data is output to the processing circuit 75.

  The camera signal processing circuit 75 performs predetermined signal processing on the output of the D-FF 74.

  The timing generator 76 generates various timing signals based on a clock supplied from a clock generation circuit (not shown). That is, the timing generator 76 generates a timing signal for driving the CCD bare chip 12 and supplies it to the driver 13, similarly to the timing generator 15 in FIG. Further, the timing generator 76 generates clocks p1, p2, and p3 having the above-described periods, and supplies the generated clocks to the A / D converter 70 and the D-FFs 72 and 73, respectively. Further, the timing generator 76 generates a clock necessary for the operation of the S / P converter 71 and supplies the clock to the S / P converter 71. The various timing signals output by the timing generator 76 are synchronized with each other (synchronized with the clock from the clock generation circuit).

  Next, the operation will be described with reference to the timing chart of FIG. Light from the subject enters the imaging lens 4, and this light is imaged on the light receiving surface of the CCD bare chip 12 by the imaging lens 4. In the CCD bare chip 12, the light received there is photoelectrically converted, and an image signal out corresponding to the light is output to the A / D converter 70 according to a timing signal from the driver 13. Here, FIG. 46A shows an image signal out output from the CCD bare chip 12.

  In the A / D converter 70, the image signal out output from the CCD bare chip 12 is supplied to the A / D converter 70 at the timing of, for example, the rising edge of the sampling clock p1 (FIG. 46B) having a half of the output cycle. The resulting digital image data sa (FIG. 46 (C)) is output to the S / P converter 71 in the form of serial data. In the S / P converter 71, the serial image data sa from the A / D converter 70 is converted into parallel image data sb (FIG. 46E) and output to the D-FF 72 and the subtraction circuit 73.

  Note that the S / P converter 71 requires one clock time for the conversion process, so that the image data sb (FIG. 46 (E)) is one clock longer than the image data sa (FIG. 46 (C)). Only delayed.

  The D-FF 72 outputs the image data from the S / P converter 71 at the timing of, for example, the rising edge of the clock p2 (FIG. 46 (D)) supplied from the timing generator 76 and having the same cycle as the sampling clock p1. sb is latched, thereby being delayed by one clock, converted into image data sc as shown in FIG. 46 (F), and output to the subtraction circuit 73.

  Here, since the clock p2 having the same cycle as the sampling clock p1 has a cycle which is の of the cycle at which the CCD bare chip 12 outputs the image signal out, the image data sb is delayed by one cycle of the clock p2. The obtained image data sc has a phase delayed from the image data sb by a time corresponding to a half of the pixel pitch of the CCD bare chip 12. Therefore, the image data sc is hereinafter appropriately referred to as half-pixel delay data sc.

  In the subtraction circuit 73, the half-pixel delay data sc output from the D-FF 72 is subtracted from the image data sb output from the S / P converter 71, and the subtraction value (difference value) sd (FIG. 46 (G)) ) Is output to the D-FF 74. The D-FF 74 latches the subtraction value sd from the subtraction circuit 73 at the timing of, for example, the rising edge of the clock p3 (FIG. 46 (H)) supplied from the timing generator 76 and having a cycle twice as long as the clock p2. Thus, image data se as shown in FIG. 46I is output to the camera signal processing circuit 75. That is, in the D-FF 74, the subtraction value sd from the subtraction circuit 73 is latched every other one and output to the camera signal processing circuit 75.

  Here, FIG. 47 shows an internal configuration example of the CCD bare chip 12 (a configuration example of a so-called FDA (Floating Diffusion Amplifier) portion). The charge generated on the light receiving surface of the CCD bare chip 12 is charged (stored) in the capacitor C, whereby a voltage change corresponding to the charge stored in the capacitor C is output from the output buffer BUF as an image signal. Then, the switch SW is turned on, whereby the capacitor C is discharged (charged to the reference potential) by applying the positive voltage E to the capacitor C, and then the switch SW is turned off and the capacitor C is turned off. Becomes a state in which the charge corresponding to the next pixel can be charged.

  In the CCD bare chip 12, an image signal is output by repeating the above operation. However, when the switch SW is turned on and off, thermal noise is generated, and a voltage corresponding to the thermal noise is generated by the capacitor. It is held at C. In the output buffer BUF, so-called 1 / f noise (fluctuation noise) is generated. For this reason, after the switch SW is turned on and further turned off (such an operation of the switch SW is hereinafter appropriately referred to as a reset), the output level of the output buffer BUF (the output of the output buffer BUF after such a reset). The level is hereinafter referred to as a precharge level as appropriate, but does not become a predetermined reference level (for example, a black level or the like), and the above-described thermal noise and 1 / f noise (hereinafter, both include noise components) Level) that reflects the effect of

  Therefore, usually, the output of the CCD bare chip 12 is subjected to the correlated double sampling processing as described in the first embodiment before the A / D conversion processing or the like, so that the image signal in which the noise component is reduced is provided. Has been made to get.

  However, when it is desired to reduce the size of the imaging device 100 incorporating the CCD bare chip 12 as much as possible and obtain digital image data as an output, for example, the output of the CCD bare chip 12 is subjected to correlated double sampling processing. Incorporating the cds processing circuit 21 shown in FIG. 22 in the imaging device 100 does not meet the demand for miniaturization.

  Therefore, in the video camera of FIG. 45, in order to respond to such a request, after the output of the CCD bare chip 12 is converted into digital image data by the A / D converter 70, the noise component is reduced as follows. It has been done.

  That is, as described above, the image signal out output from the CCD bare chip 12 includes, as shown in FIG. 46A, a precharge portion (a portion shown by a dotted line in the figure) at a precharge level and a capacitor. And a signal portion (indicated by a solid line in the drawing) having a level (signal level) corresponding to the charge charged in C. Then, from the above-described principle of the generation of the noise component, there is a correlation between the noise component included in a certain signal portion and the noise component included in the immediately preceding precharge portion. That is, the noise component included in a certain signal portion is substantially equal to the precharge level immediately before. Therefore, by subtracting the precharge level immediately before from the signal level of a certain signal section, a true signal component of the signal section can be obtained.

  The D-FF 72, the subtraction circuit 73, and the D-FF 74 perform processing corresponding to the above-described principle on the image data sa from the A / D converter 70 to obtain image data with reduced noise components. It has been made.

  That is, in the A / D converter 70, as described above, the image signal out from the CCD bare chip 12 is supplied to the A / D converter 70 at the timing of the sampling clock p1 (FIG. 46B) having a half of the output cycle. As a result, the digital image data sa obtained as a result has signal levels (vi) and precharge levels (fi) alternately arranged as shown in FIG. 46 (C). In FIG. 46 (C) (the same applies to FIGS. 46 (E) and 46 (F)), the signal level or the precharge level is indicated by adding a numeral to v or f, respectively. The same numbers are given to the signal level and the precharge level (a certain signal level and the precharge level immediately before it) to be combined.

  The image data sb or the half-pixel delay data sc input to the subtraction circuit 73 is obtained by delaying the image data sa (converted into parallel data) by one clock or two clocks, respectively. The result is as shown in FIG. 46 (E) or FIG. 46 (F). Further, in the subtraction circuit 73, the half-pixel delay data sb is subtracted from the image data sb, and among the subtraction values sd, those obtained from the signal level and the precharge level to be paired have noise components. It becomes reduced image data (hereinafter, referred to as true image data as appropriate). That is, every other subtraction value sd becomes true image data as shown by adding a numeral to v 'in FIG. 46 (G). In FIG. 46 (G), v '# i (#i is an integer) represents the calculation result of v # if-i, and x represents invalid data.

  Accordingly, the D-FF 74 latches the subtraction value sd at every other clock at the timing of the clock p3 as shown in FIG. 46H, so that the true image data se is transmitted to the camera signal processing circuit 75. (FIG. 46 (I)) is supplied.

  In addition, according to the subtraction processing in the subtraction circuit 73, the number of effective bits is reduced. However, the influence of this is almost ignored by appropriately setting the reference voltage vref applied to the A / D converter 70. can do.

  In the camera signal processing circuit 75, the image data se is converted into an analog signal, for example, as shown in FIG. 46 (J), and is recorded on a video tape or the like.

  As described above, since image data is digitally output from the imaging apparatus 100, it is possible to easily configure an apparatus incorporating the image data.

  Further, the A / D converter 70 performs the A / D conversion at the timing of the sampling clock p1 having a half of the output cycle of the image signal out from the CCD bare chip 12, so that the Noise components included in data can be easily reduced. As a result, it is not necessary to provide a circuit for reducing such a noise component in the imaging device 100, and a small-sized imaging device that outputs digital image data can be realized.

[Fourth embodiment]
It is conceivable that the above-described imaging device is mounted on a personal computer for use. FIG. 48 shows the external configuration of such a personal computer. That is, the keyboard 242 is formed on the upper surface of the main body 241 side of the notebook type personal computer 240, and the FD mounting part 244 and the PC card mounting part 245 are formed on the side surface of the main body 241. A PC card 246 is mounted on the PC card mounting section 245 as needed, and can be taken out when not used. The LCD 243 is rotatably supported by the main body 241 and displays image information such as predetermined characters and figures.

  FIG. 49 shows the external configuration of the PC card 246. In this embodiment, the PC card 246 has a length of 85.6 mm, a width of 54.0 mm, and a height (thickness) of 10.5 mm. This shape is defined as a PCMCIA (Personal Computer, Memory Card, International Association) standard type 3 card.

  As shown in FIG. 50, the PC card 246 has a housing 301, and a slide member 302 is slidably held on the housing 301. The imaging device 100 is rotatably supported by the slide member 302 via a support member 303. When the slide member 302 enters the inside of the housing 301, the imaging device 100 is also completely housed inside the housing 301.

  For example, when the personal computer 240 is connected to a communication line such as a telephone line to perform a videophone call or a video conference, a PC card 246 is mounted on the PC card mounting portion 245 as shown in FIG. In contrast, the imaging device 100 is pulled out of the personal computer 240 by sliding the slide member 302. Further, as shown in FIG. 51, the imaging device 100 is rotated in a range of about 60 to 90 degrees with the support member 303 as a fulcrum, and the hole 3 (imaging lens 4) of the imaging device 100 is ).

  FIG. 52 illustrates an example of the internal configuration of the imaging device 100 housed in the housing 301 of the PC card 246, that is, a fourth embodiment.

  This embodiment has basically the same configuration as the first embodiment shown in FIG. However, the light receiving surface (imaging surface) (the upper surface in FIG. 52) of the CCD bare chip 12 is formed on the substrate 1 on the back side of the substrate 1 (the side opposite to the imaging lens 4) by a flip chip mounting method. It is mounted so as to face the imaging lens 4 via the hole 231 provided. A projection 233 is formed on the substrate 1 in order to regulate the position where the CCD bare chip 12 is mounted.

  An imaging lens 4 is mounted on the upper surface side of the substrate 1 in the figure (opposite to the surface on which the CCD bare chip 12 is mounted). A projection 232 is formed on the substrate 1 in order to regulate the mounting position of the imaging lens 4. By mounting the CCD bare chip 12 at a predetermined position using the projection 233 as a guide and mounting the imaging lens 4 at a predetermined position using the projection 232 as a guide, the imaging lens 4 and the CCD bare chip 12 are connected to the hole 231 of the substrate 1. Are arranged so as to face each other at a predetermined relative position.

  A driver 13 and an A / D converter 14 are arranged on the upper surface of the substrate 1, and other components 234 are mounted on the lower surface of the substrate 1.

  At a predetermined position of the package 2A, a hole 3 functioning as an aperture is formed. When the package 2A is bonded to the substrate 1 via the filler 20, light incident through the hole 3 is condensed. The light enters the image lens 4. This light is condensed by the imaging lens 4 and is incident on the light receiving surface (imaging surface) of the CCD bare chip 12 through the hole 231 of the substrate 1.

  Further, in this embodiment, a predetermined gap is provided between the package 2A and the imaging lens 4, so that when the package 2A receives an external force, the force is not directly transmitted to the imaging lens 4. I have.

  In this embodiment, the distance from the upper end of the package 2A to the upper end of the imaging lens 4 is 1.5 mm, the thickness of the imaging lens 4 is 2.0 mm, and the distance between the lower end of the imaging lens 4 and the substrate 1 The distance to the upper surface is 4.0 mm, the thickness of the substrate 1 is 0.5 mm, and the distance from the lower surface of the substrate 1 to the lower end of the CCD bare chip 12 and the component 234 mounted on the lower surface of the substrate 1 is 1. It can be 0 mm. In particular, by mounting the CCD bare chip 12 on the main body side with the imaging lens 4 via the substrate 1, the substrate 1 can be arranged within the focal length of the imaging lens 4, so that the embodiment shown in FIG. It is possible to further reduce the thickness as compared with. As a result, the total thickness of this example is 9.0 mm. Further, the horizontal length and the vertical length of the imaging device 100 can be set to 15 mm. Therefore, as shown in FIGS. 50 and 51, the imaging device 100 can be housed inside the housing 301 of the PC card 246 having a thickness of 10.5 mm.

  FIG. 53 shows an example of an electrical configuration inside the personal computer 240. The CPU 311 executes various processes according to a program stored in the ROM 312. The RAM 313 appropriately stores programs and data necessary for the CPU 311 to execute various processes.

  A keyboard 242, a PC card driver 315, an FD driver 316, and a modem 318 are connected to the input / output interface 314 connected to the CPU 311 via the bus. The PC card driver 315 transfers various data to and from the PC card 246 when the PC card 246 is mounted. Further, the FD driver 316 records or reproduces data with respect to the floppy disk 317 when the floppy disk (FD) 317 is mounted. The modem 318 is connected to a communication line such as a telephone line, receives and demodulates data input through the communication line, outputs the data to the CPU 311, modulates data supplied from the CPU 311, and Output.

  An LCD driver 319 for driving the LCD 243 is connected to the input / output interface 314. The audio signal input from the microphone 320 is A / D-converted by the A / D converter 321 and then input to the input / output interface 314. The audio data output from the input / output interface 314 is D / A converted by the D / A converter 322 and then output from the speaker 323.

  Next, the operation will be described. For example, when making a videophone call with a predetermined party, the user mounts the PC card 246 on the PC card mounting section 245, pulls out the imaging device 100 from the PC card 246, and further rotates at a predetermined angle, as shown in FIG. Point in your direction as shown.

  Next, the user operates the keyboard 242 to input the telephone number of the other party. When receiving the input of the telephone number, the CPU 311 controls the modem 318 via the input / output interface 314 to execute a calling operation for the telephone number.

  The modem 318 performs a call operation to the other party in response to a command from the CPU 311 and, when the other party responds to the call operation, notifies the CPU 311 to that effect.

  At this time, the CPU 311 controls the PC card 246 via the PC card driver 315 and causes an image signal to be captured.

  In the imaging device 100, after the user's image is photoelectrically converted by the CCD bare chip 12 via the imaging lens 4, the image is A / D converted by the A / D converter 70 and output to the PC card driver 315. The PC card driver 315 outputs the image data, which has been converted into data in a format conforming to the PCMCIA standard, to the CPU 311 via the input / output interface 314. The CPU 311 supplies the image data to the modem 318 via the input / output interface 314 and causes the modem 318 to transmit the image data to the other party via the communication line.

  On the other hand, when the image data of the other party having the same device is sent via the communication line, the modem 318 receives and demodulates the data and outputs it to the CPU 311. When receiving the image data, the CPU 311 outputs the image data to the LCD driver 319 and causes the LCD 243 to display the image data. As a result, the image of the other party is displayed on the LCD 243.

  On the other hand, an audio signal that the user speaks toward the other party is captured by the microphone 320 and A / D converted by the A / D converter 321. The modem 318 transmits the audio data to the other party via a communication line under the control of the CPU 311.

  The voice data transmitted from the other party is demodulated by the modem 318. This demodulated audio data is D / A converted by the D / A converter 322 and then emitted from the speaker 323.

  In this manner, the user can easily make a videophone call simply by attaching the PC card 246 having an imaging function to the personal computer 240.

  In the above embodiment, the imaging lens is constituted by one lens. However, as shown in FIG. 44, the imaging lens may be constituted by a plurality of lenses. .

1 is a perspective view illustrating a configuration of an embodiment of an imaging device to which the present invention has been applied. It is a top view of the imaging device of FIG. FIG. 3 is a cross-sectional view taken along the line A-A ′ of the imaging device in FIG. 2. FIG. 4 is a diagram illustrating a configuration example of a CCD bare chip 12 in FIG. 3. FIG. 3 is a perspective view illustrating a configuration of a lens unit 10. It is an enlarged view of the part shown by Z of FIG. FIG. 7 is a diagram illustrating another configuration example of the embodiment in FIG. 6. FIG. 7 is a diagram showing still another configuration example of the embodiment in FIG. 6. FIG. 3 is a diagram for explaining optical characteristics of the imaging lens 4 and dimensions (length) of a leg 11. FIG. 4 is a diagram illustrating a spatial frequency response characteristic of the imaging lens 4. FIG. 3 is a diagram illustrating an arrangement position of an imaging surface. It is a figure showing other examples of arrangement of an imaging side. FIG. 3 is a diagram illustrating a range in which an image is to be uniformed. FIG. 3 is a diagram illustrating the curvature of an image forming surface. FIG. 3 is a diagram illustrating pixels on a CCD bare chip. FIG. 4 is a diagram illustrating a change in an image forming position. FIG. 4 is a diagram illustrating a relationship between a focal length and a focus shift amount. FIG. 4 is a diagram for explaining a method for manufacturing the imaging device of FIG. 1. FIG. 4 is a diagram for explaining a method for manufacturing the imaging device of FIG. 1. It is a figure which shows the example of formation of a holder. It is a figure showing other examples of formation of a holder. FIG. 2 is a block diagram illustrating a configuration example of a video camera to which the imaging device in FIG. 1 is applied. FIG. 3 is a diagram illustrating a state in which light L emitted from an imaging lens and not captured by an imaging target is reflected by a leg. It is a figure showing other examples of composition of a lens part. FIG. 14 is a diagram illustrating another configuration example of the imaging device. It is a figure explaining the change of the focal length of a lens part, and a leg part. FIG. 4 is a diagram illustrating an example in which a discontinuous surface is formed on an imaging lens 4. FIG. 28 is a diagram illustrating a configuration of the embodiment of FIG. 27 when viewed from above. FIG. 28 is a diagram illustrating MTF characteristics of the example in FIG. 27. FIG. 9 is a diagram illustrating another example of forming the discontinuous surface of the imaging lens 4. It is a figure which shows the other example of assembly with respect to the board | substrate of a CCD bare chip and a lens part. FIG. 32 is a diagram showing an assembling process of the embodiment in FIG. 31. FIG. 32 is a diagram illustrating a configuration example of a lens unit in FIG. 31. FIG. 32 is a diagram illustrating another configuration example of the lens unit in FIG. 31. It is a block diagram showing other examples of composition of an imaging device. FIG. 11 is a perspective view illustrating a configuration of another example of an imaging device. FIG. 37 is a plan view of the imaging device in FIG. 36. FIG. 38 is a sectional view taken along the line B-B ′ of the imaging device in FIG. 37. FIG. 38 is a cross-sectional view of the C-C ′ part of the imaging device of FIG. 37. It is a figure showing other examples of formation of a holder. It is a figure showing other examples of formation of a holder. It is a figure showing other examples of formation of a holder. FIG. 40 is a diagram showing a modification of the embodiment in FIG. 39. FIG. 9 is a diagram illustrating another configuration example of the imaging lens. FIG. 1 is a block diagram illustrating a configuration example of a video camera to which the present invention has been applied. 46 is a timing chart for explaining the operation of the video camera in FIG. 45. FIG. 2 is a diagram showing an example of the internal configuration of a CCD bare chip 12; FIG. 3 is a diagram illustrating a use state of a PC card. FIG. 2 is a diagram illustrating a configuration of a PC card. FIG. 4 is a diagram showing a state in which a PC card is mounted on a personal computer. FIG. 2 is a diagram illustrating a state in which an imaging device is used in a personal computer. FIG. 51 is a diagram illustrating an example of the internal configuration of the imaging device in FIG. 50. FIG. 49 is a block diagram illustrating an example of the internal configuration of the personal computer in FIG. 48. FIG. 11 is a diagram illustrating a configuration of an example of a conventional video camera. FIG. 11 is a diagram illustrating a configuration example of a conventional imaging device. FIG. 55 is a diagram illustrating a configuration example of the CCD imaging device in FIG. 55.

Explanation of reference numerals

  1 substrate, 2 holders, 2A package, 3 holes, 4 imaging lens, 10 lens unit, 11 legs, 11A notch, 12 CCD bare chip (charge coupled device), 13 driver, 14 A / D converter, 15 timing Generator, 16 memories (two-port memory), 21 cds (correlated double sampling) processing circuit, 22 accumulator, 51 substrate, 52 holder, 54 imaging lens, 61 light shielding film, 62 legs, 62A cutout, 70 A / D converter, 71 S / P converter, 72 D-FF (D flip-flop), 73 subtraction circuit, 74 D-FF, 76 timing generator, 100 imaging device, 101 lens module, 102 imaging lens, 103 iris adjustment Mechanism, 104 for Surenzu, 111 camera, 112 an optical LPF (low pass filter), 113 image sensor, 114 camera processing circuit

Claims (11)

One imaging lens for imaging light;
A photoelectric conversion element that photoelectrically converts the light imaged by the imaging lens and outputs an image signal;
The imaging device, wherein a part of the imaging lens is in direct contact with the photoelectric conversion element. The imaging device according to claim 1, wherein the imaging lens has a plurality of legs, and the plurality of legs are in direct contact with the photoelectric conversion element. The imaging device according to claim 1, wherein the plurality of legs have characteristics of preventing light incident thereon from reaching the photoelectric conversion element. The imaging device according to claim 1, wherein the leg has three or more side surfaces, and two of the side surfaces are opposed to an optical axis of the imaging lens. A photoelectric conversion element that photoelectrically converts light incident on the light receiving surface and outputs an image signal;
An A / D converter for A / D converting the image signal output from the photoelectric conversion element,
The imaging device, wherein the photoelectric conversion element and the A / D converter are incorporated in one package. The imaging device according to claim 5, wherein the A / D converter is a serial output type A / D converter. The package includes:
Generating means for generating a luminance signal or R, G, B signals from an output of the A / D converter;
The imaging apparatus according to claim 5, further comprising: serial data transfer means for outputting an output of the generation means to the outside as serial data, and for receiving serial control data from the outside. The photoelectric conversion element is a charge-coupled element,
6. The A / D converter according to claim 5, wherein the A / D converter converts the image signal at a timing of a clock having a half of a period at which the charge coupled device outputs the image signal. An imaging device according to item 1. The imaging device according to claim 5, further comprising a memory that stores an output of the A / D converter. A signal processing device for processing digital image data obtained by A / D converting an image signal output from a charge-coupled device,
When the image data is obtained by A / D converting the image signal at a timing of a clock having a half of a cycle at which the charge coupled device outputs the image signal,
Delay means for delaying the image data by one clock;
Calculating means for calculating a difference between the image data and an output of the delay means;
An output unit that outputs the difference output from the arithmetic unit every other interval. A signal processing method for processing digital image data obtained by A / D converting an image signal output from a charge-coupled device,
When the image data is obtained by A / D converting the image signal at a timing of a clock having a half of a cycle at which the charge coupled device outputs the image signal,
Delaying the image data by one clock;
Calculating a difference between the image data and the image data delayed by the one clock;
Outputting the difference every other one.

Images