JP2005027105A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus with a simple configuration and advantageous for downsizing capable of carrying out ordinary photographing and reading a data symbol with a high resolution at a near distance. <P>SOLUTION: The imaging apparatus has an ordinary photographing mode and a data symbol read mode. A photographing lens 6 of the imaging apparatus comprises: a lens body 60 having a first lens section 61 and a second lens section 62 of nearly annular shape provided to an outer circumferential part; a first film 64 acting like an optical filter for transmitting a near infrared ray and provided to the first lens section 61; and a second film 65 acting like an optical filter for transmitting a visual light and provided to the second lens section 62. The first lens section 61 is used for reading the data symbol. A focal distance f1 of the second lens section 62 is specified to be longer than a focal distance f1 of the first lens section 61 and the second lens section 62 is used for ordinary photographing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus.
[0002]
[Prior art]
2. Description of the Related Art Devices that can read data symbols (codes) such as barcodes and two-dimensional codes in imaging devices that employ pan focus of small portable terminals such as cellular phones are known.
[0003]
However, with this imaging device, it is difficult to enter a focus range up to a short distance, for example, about 10 cm. For this reason, sufficient resolution cannot be obtained in reading data symbols, and the amount of data symbols that can be read cannot be increased.
[0004]
There is also known an imaging apparatus that can switch between normal imaging and macro imaging by moving the lens and changing the lens configuration (see, for example, Patent Document 1).
[0005]
However, the imaging apparatus described in Patent Document 1 requires a mechanism for moving the lens, which complicates the structure and increases the size of the entire apparatus.
[0006]
[Patent Document 1]
JP 2002-107612 A
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide an imaging apparatus that has a simple configuration and is advantageous for downsizing, and that can perform normal photographing and reading of data symbols at high resolution at a short distance.
[0008]
[Means for Solving the Problems]
Such an object is achieved by the present inventions (1) to (12) below.
[0009]
(1) A normal shooting mode that includes a shooting optical system that forms an image of a subject, and an imaging unit that has a light receiving surface arranged at an image forming position by the shooting optical system, and reading of data symbols An imaging device having a data symbol reading mode for performing
The imaging optical system is used when reading data symbols, and a first lens unit having a first focal length;
A second lens unit that is used in normal photographing, is provided on the outer peripheral side of the first lens unit, and has a second focal length longer than the first focal length;
A first filter provided in the first lens portion and transmitting light in a first wavelength band;
An imaging apparatus comprising: a second filter that is provided in the second lens portion and transmits light in a second wavelength band.
Thereby, normal photographing and reading of data symbols (codes) can be surely performed, and in particular, data symbols can be read at a short distance and with high resolution.
In addition, since it is not necessary to provide a mechanism for moving the photographing optical system, the configuration is simple and the size can be reduced.
[0010]
(2) The imaging device according to (1), wherein the second lens unit has an annular shape.
As a result, the size of the photographing optical system can be further reduced, and the entire apparatus can be reduced in size.
[0011]
(3) The imaging device according to (1) or (2), wherein the first lens unit and the second lens unit are integrally formed.
Thereby, the number of parts can be reduced and assembly can be performed easily.
[0012]
(4) The imaging device according to any one of (1) to (3), wherein a region of the first lens unit is smaller than a region of the second lens unit.
Thereby, the depth of field in the first lens unit can be deepened (widened), and data symbols can be read more reliably.
[0013]
(5) The imaging device according to any one of (1) to (4), wherein an optical axis of the first lens unit and an optical axis of the second lens unit substantially coincide with each other.
Thereby, size reduction can be achieved.
[0014]
(6) The imaging device according to any one of (1) to (5), wherein the first wavelength band is a near infrared region.
Thereby, the data symbol can be reliably read by the infrared light illumination and the visible light suppression by the housing.
[0015]
(7) The imaging device according to any one of (1) to (6), wherein the second wavelength band is a visible light range.
Thereby, the data symbol can be reliably read by the infrared light illumination and the visible light suppression by the housing.
[0016]
(8) The imaging device according to any one of (1) to (7), further including a strobe device that emits light in the first wavelength band.
Accordingly, the area of the first lens unit can be reduced, and the depth of field in the first lens unit can be increased (widened), whereby the data symbol can be read more reliably. be able to.
In addition, data symbols can be reliably read by infrared light illumination and visible light suppression by the housing.
[0017]
(9) The imaging device according to (8), wherein when reading a data symbol, light of the first wavelength band is emitted from the strobe device.
Accordingly, the area of the first lens unit can be reduced, and the depth of field in the first lens unit can be increased (widened), whereby the data symbol can be read more reliably. be able to.
In addition, data symbols can be reliably read by infrared light illumination and visible light suppression by the housing.
[0018]
(10) The imaging device according to (8) or (9), wherein the strobe device is configured by an LED.
Thereby, the strobe device can be miniaturized.
[0019]
(11) The imaging device according to (10), wherein the light of the first wavelength band is irradiated by continuously lighting the LED.
Thereby, the position of the data symbol can be reliably confirmed in the state where the visible light is blocked by the casing, and the data symbol can be put in the reading range (a region where the data symbol can be read).
[0020]
(12) detection means for detecting the distance to the subject;
(1) to (11) further comprising mode setting means for selecting one of the normal photographing mode and the data symbol reading mode and setting the mode based on the detection result of the detection means. The imaging device according to any one of the above.
As a result, the normal shooting mode and the data symbol reading mode are automatically set, so that the operation does not take time and the mode can be switched to an appropriate mode without fail.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an imaging device of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.
[0022]
Here, although the following embodiment demonstrates the case where the imaging device of this invention is applied to an electronic camera (digital camera), the use of the imaging device of this invention is not limited to this.
[0023]
FIG. 1 is a front view showing an embodiment of the imaging apparatus of the present invention, FIG. 2 is a block diagram showing a circuit configuration of the imaging apparatus shown in FIG. 1, and FIG. 3 shows an optical system of the imaging apparatus shown in FIG. It is sectional drawing.
[0024]
The imaging apparatus 1 shown in these drawings has two modes, ie, a normal shooting mode for normal shooting and a data symbol reading mode for reading data symbols (codes) as shooting modes. This is an imaging device that employs pan focus.
[0025]
As shown in FIG. 1, the imaging device 1 has a box-shaped body 10, and a photographing lens 6, a light emitting unit 18 of a strobe device for normal photographing, and a data symbol reading are provided on the front surface (front surface) of the body 10. The light emitting unit 20 and the pair of distance measuring windows 44 of the strobe device, the back of the body 10, a viewfinder (not shown), the loading slot for the IC memory card 40 and the display unit 13 (see FIG. 2), On the upper surface, release switches 121 are respectively installed.
[0026]
The imaging apparatus 1 has a photographing optical system 2 shown in FIG. A CCD (imaging device) 8 is installed at an imaging position behind the photographic optical system 2 (lower side in FIG. 3). The CCD 8 is configured such that a large number of pixels are arranged in a matrix, each of the pixels accumulates a charge corresponding to the amount of received light, and sequentially transfers the charge at a predetermined time.
[0027]
The image pickup apparatus 1 of the present embodiment is an apparatus for photographing a color image. As the CCD 8, for example, a CCD provided with a primary color filter is used. That is, each pixel of the CCD 8 is covered with a filter for extracting (transmitting) red (R), green (G), and blue (B). The filter for extracting red transmits not only the red component but also near infrared light (wavelength band in the near infrared region).
[0028]
In normal photographing, RGB components of each pixel are calculated by a plurality of pixels having filters for taking out red, green and blue of the CCD 8 (color interpolation). In reading data symbols, only pixels having a filter for taking out red of the CCD 8 constitute the pixels.
[0029]
Light from the subject passes through the taking lens 6, passes through the optical low-pass filter 7, and reaches the light receiving surface of the CCD 8. In this way, the subject image is formed on the light receiving surface of the CCD 8.
[0030]
The main part of the image pickup unit in the image pickup apparatus 1 includes the CCD 8 and a CCD drive circuit 21 described later.
[0031]
In the present invention, a CCD having a configuration other than that described above may be used as the image sensor, and an image sensor other than the CCD may be used.
[0032]
Next, the photographing optical system 2 will be described.
As shown in FIG. 3, a substrate 51 is installed in the body 10, and a cylindrical attachment portion 52 is installed on the substrate 51. The attachment portion 52 is fixed to the body 10.
[0033]
The CCD 8 is installed inside the mounting part 52 on the substrate 51, and the photographing optical system 2 is installed in the mounting part 52. The photographic optical system 2 includes a photographic lens 6 having a holding portion 63 on the outer periphery and an optical low-pass filter 7.
[0034]
The CCD 8, the optical low-pass filter 7 and the photographing lens 6 are arranged in this order from the lower side (substrate 51 side) to the upper side in FIG.
[0035]
An annular spacer 54 is provided between the CCD 8 and the optical low-pass filter 7.
[0036]
Further, the holding portion 63 of the photographing lens 6 is sandwiched between the annular frame member 53 and the attachment portion 52, whereby the photographing lens 6 is fixed (held) to the attachment portion 52.
[0037]
The photographic lens 6 includes a lens body 60 having a first lens portion 61 and a second lens portion 62, a first film (first filter) 64, and a second film (second filter). 65.
[0038]
The shape of the first lens portion 61 in a plan view (the shape when viewed from the upper side in FIG. 3) is substantially circular. The first lens unit 61 is used when reading data symbols (in the data symbol reading mode), and is configured to focus on a predetermined distance a to b.
[0039]
The distance (lower limit value) a and the distance (upper limit value) b are appropriately determined according to various conditions. The distance a is preferably about 3 to 6 cm, for example, and the distance b is For example, it is preferably about 10 to 15 cm.
[0040]
The shape of the second lens portion 62 in plan view is substantially annular (annular), and the second lens portion 62 is provided on the outer peripheral portion (outer peripheral side) of the first lens portion 61. Yes. The focal length f2 of the second lens unit 62 is set longer than the focal length f1 of the first lens unit 61. That is, the second lens unit 62 is used during normal shooting (in the normal shooting mode) and is configured to focus on a predetermined distance c to ∞.
[0041]
Although the said distance (lower limit) c is suitably determined according to various conditions, it is preferable that it is about 0.5-0.8 m, for example.
[0042]
A holding portion 63 is provided on the outer peripheral portion of the second lens portion 62. The first lens unit 61, the second lens unit 62, and the holding unit 63 are integrally formed (one member).
[0043]
In addition, the optical axis of the first lens unit 61 and the optical axis of the second lens unit 62 substantially coincide with each other.
[0044]
Further, the area of the first lens unit 61 (area in plan view) is set smaller than the area of the second lens unit 62.
[0045]
In this case, when the area (projection area) of the first lens unit 61 in plan view is S1, and the area of the second lens unit 62 in plan view is S2, the ratio S1 / S2 is 1 / It is preferably about 8 to 1/15.
[0046]
Here, the focal length f1 of the first lens unit 61 is preferably about 1.4 to 1.8 mm.
[0047]
The aperture Φ1 of the first lens unit 61 is preferably about 0.8 to 1.4 mm.
[0048]
Moreover, it is preferable that the focal length f2 of the 2nd lens part 62 is about 2.4-3 mm.
[0049]
Moreover, it is preferable that the aperture diameter Φ2 of the second lens portion 62 is about 3.5 to 5 mm.
[0050]
In the present embodiment, for example, in the CCD size 1/7 type, the first lens unit 61 having a focal length f1 of 1.6 mm, an aperture Φ1 of 1 mm, and an F number of F11 can be used. As the second lens unit 62, one having a focal length f2 of 2.6 mm, a diameter Φ2 of 4 mm, and an F number of F2.8 can be used. Needless to say, the present invention is not limited to this.
[0051]
Each characteristic such as the focal length of the first lens unit 61 and the second lens unit 62 can be set as desired by adjusting, for example, the refractive index and the curvature.
[0052]
A first film 64 is provided on the surface of the first lens portion 61 on the CCD 8 side (lower side in FIG. 3). The first film 64 is schematically shown by a dotted line in FIG. 3 in order to distinguish it from the second film 65. In the present embodiment, an optical filter that transmits light in the near infrared region (first wavelength band) (near infrared light) is used as the first film 64. Specifically, for example, an optical filter that transmits light having a wavelength of about 650 to 700 nm can be used.
[0053]
A second film 65 is provided on the surface of the second lens portion 62 on the CCD 8 side. The second film 65 is schematically shown by a solid line in FIG. In the present embodiment, an optical filter that transmits light (visible light) in the visible light region (second wavelength band) is used as the second film 65. Specifically, for example, an optical filter that transmits light having a wavelength of about 400 to 650 nm can be used.
[0054]
FIG. 4 is a graph showing characteristics of the first film and the second film provided in the photographing lens of the imaging apparatus shown in FIG. In this graph, the horizontal axis represents the wavelength of light, and the vertical axis represents the light transmittance.
[0055]
In the present embodiment, for example, the first film 64 and the second film 65 having the characteristics shown in FIG. 4 can be used. Needless to say, the present invention is not limited to this.
[0056]
In the present invention, the photographing lens 6 is not limited to the shape described above. For example, as shown in FIG. 5, the subject side (upper side in FIG. 5) of the lens body 60 of the photographic lens 6 has a uniform curvature, and the CCD 8 side (lower side in FIG. 5) is described above at the center and peripheral parts of the lens. It can also be designed to be equivalent to the photographing lens 6 shown in FIG. In this case, the first film 64 and the second film 65 are provided on the CCD 8 side (lower side in FIG. 5), that is, on the surface where the curvature is changed.
[0057]
In the present invention, the first lens portion 61 and the second lens portion 62 may be formed of separate members.
[0058]
FIG. 6 is a plan view showing a configuration example of data symbols.
In the configuration shown in FIG. 6, the data symbol (code) 38 is configured by a black or white (or transparent) mosaic arranged in x rows × y columns (x and y are integers of 2 or more). The black or white color of the mosaic represents, for example, 0 or 1 in the binary system, and desired information is specified by this combination. The data symbol 38 is not limited to the one shown in the figure, and includes, for example, a barcode.
[0059]
As illustrated in FIG. 2, the imaging apparatus 1 includes a control unit 11. The control means 11 is usually composed of a microcomputer (CPU), and performs control of various functions in the imaging apparatus 1 such as sequence control, distance measurement, exposure calculation, execution of automatic exposure, mode setting, strobe drive, and the like. In addition, as described later, the information represented by the data symbol 38 is decoded (decoded). The main functions of the decoding means, the determining means and the mode setting means are achieved by this control means 11.
[0060]
The control means 11 includes a RAM (rewritable memory) 35.
[0061]
The control unit 11 is connected to an operation unit 12, a display unit (display unit) 13 that is a notification unit, and an EEPROM (rewritable nonvolatile memory) 32. The operation unit 12 includes, for example, a main switch (power switch), a release switch 121, an eject switch for ejecting the IC memory card 40, and the like.
[0062]
The display unit 13 includes an area on the memory of the IC memory card 40 for storing information such as whether the main switch is turned on / off, shooting date, whether the IC memory card 40 is loaded, and image signals. Necessary information out of the information on the strobe light emission and the current time is displayed by, for example, a liquid crystal display element (LCD) or a light emitting element.
[0063]
The imaging device 1 also has a power supply circuit 14 for supplying power. A battery 15 is connected to the power supply circuit 14 and a terminal for connection to the external power supply circuit 16 is provided.
[0064]
Further, the imaging apparatus 1 includes an interface circuit 33 connected to the control unit 11, and the external connection terminal (output terminal) 34 is connected to the interface circuit 33. For example, a communication cable for communicating with an external device (for example, a host computer or the like) of the imaging apparatus 1 is connected to the external connection terminal 34 (none of which is shown). Communication is possible. The control means 11 has a function of outputting a signal to the external connection terminal 34 via the interface circuit 33, and is input from an external device connected to the external connection terminal 34 via a communication cable. A predetermined signal is output to the outside based on a command signal or the like.
[0065]
The control unit 11 is connected to a normal photographing strobe driving circuit 17 and a data symbol reading strobe driving circuit 19. The control means 11 causes the light emitting portion 18 of the strobe device for normal photographing to emit light via the strobe driving circuit 17 for normal photographing, and the strobe for reading data symbols via the data symbol reading strobe driving circuit 19. The light emitting unit 20 of the apparatus is caused to emit light.
[0066]
It is preferable that the light emitting unit 20 of the strobe device for reading data symbols is composed of an LED (light emitting diode). And it is preferable to irradiate near-infrared light (light of a 1st wavelength band) by the continuous lighting of this light emission part 20. FIG.
[0067]
In addition, the imaging apparatus 1 includes distance measuring means (detecting means) that measures (detects) a distance from the imaging apparatus 1 to a subject (subject distance). In the present embodiment, two sets of PSDs 42 and lenses 43 that are sensors configured by an array of photodiodes, and a distance measuring unit 41 are provided as a detection means of an external light triangular type passive method. The distance measuring unit 41 obtains the distance from the imaging device 1 to the subject based on the signal input from each PSD 42 and inputs (sends) the information (ranging information) to the control unit 11.
[0068]
In the present invention, the detection means for detecting the distance to the subject is not limited to the above-described one, and may be, for example, another passive method, an active method, or the like.
[0069]
The detection of the distance to the subject is not limited to the case of obtaining (detecting) the distance itself, but includes, for example, the case of obtaining a physical quantity corresponding to the distance to the subject.
[0070]
The release switch 121 is a two-stage switch. In the photographing mode, when the first step of the release switch 121 is turned on, the distance measuring unit is operated. When the second step is turned on, the CCD 8 is driven by the CCD driving circuit 21 to perform photographing (photographing). . In this case, normal shooting is performed in the normal shooting mode, and the data symbol 38 is read in the data symbol reading mode.
[0071]
In addition, the imaging apparatus 1 includes a CCD drive circuit 21, a synchronization signal generation circuit 22, an address control circuit 23, a CCD signal processing circuit 24, an A / D converter 25, a main memory 26, an image processing unit 27, an image compression circuit 28, A memory card control circuit 29, a binarization circuit 36, a loading unit 30 for loading an IC memory card 40, and a detecting means 31 for detecting loading of the IC memory card 40 into the loading unit 30 are provided. The CCD signal processing circuit 24, the A / D converter 25, the image processing unit 27, and the main memory 26 constitute a signal processing circuit that generates an image signal.
[0072]
The synchronization signal generation circuit 22 receives a control signal from the control means 11, generates a clock signal based on the control signal, and generates a synchronization signal (horizontal synchronization signal, vertical synchronization signal, etc.) based on the clock signal. . The generated clock signal and synchronization signal are input to the CCD drive circuit 21 and the address control circuit 23, respectively, and used for each operation.
[0073]
The address control circuit 23 generates various pulse signals based on the synchronization signal and the clock signal input from the synchronization signal generation circuit 22.
[0074]
The CCD drive circuit 21 drives the CCD 8 based on the synchronization signal input from the synchronization signal generation circuit 22.
[0075]
In this case, visible light from the subject is blocked by the first film 64 in the first lens portion 61 of the photographing lens 6, and transmitted through the second film 65 in the second lens portion 62, and the optical low-pass filter 7. After that, it reaches the light receiving surface of the CCD 8. In this way, the subject image is formed on the light receiving surface of the CCD 8 (see FIG. 3).
[0076]
In the normal shooting mode, when the second stage of the release switch 121 is turned on, charges corresponding to the amount of light corresponding to the subject image are accumulated in each pixel of the CCD 8, and the accumulated charges are The data are sequentially transferred and input to the CCD signal processing circuit 24.
[0077]
The CCD signal processing circuit 24 performs predetermined signal processing on the signal output from the CCD 8, and the primary colors relating to analog image signals of the photographed subject image, that is, red (R), green (G), and blue (B). An analog image signal is obtained.
[0078]
Here, as described above, the filter for taking out red of the CCD 8 is configured to transmit the red component and near infrared light (wavelength band in the near infrared region), so the analog image signal of red is In this normal photographing, near infrared light is cut by the second film 65 on the second lens 62 portion side, and corresponds to the red component and near infrared light. Although some near infrared light that has passed through a narrow range (region) of the lens unit 61 is included, there is substantially no influence.
[0079]
This primary color analog image signal is converted into a digital image signal, that is, a primary color digital image signal of red, green and blue by the A / D converter 25, and predetermined data processing such as pixel interpolation processing (image is performed by the image processing unit 27). Processing) and is temporarily stored at a predetermined address in the main memory 26.
[0080]
In this case, the address control circuit 23 operates a built-in address counter based on the synchronization signal from the synchronization signal generation circuit 22 to write each primary color digital image signal to a predetermined address in the main memory 26. .
[0081]
The address control circuit 23 operates a built-in read address counter based on the clock signal from the control means 11 to read each primary color digital image signal from a predetermined address in the main memory 26.
[0082]
The read primary color digital image signals are respectively input to the memory card control circuit 29. In the memory card control circuit 29, the image compression circuit 28 controlled by the control means 11 outputs a primary color digital image signal obtained by compressing the input primary color digital image signal to a predetermined amount.
[0083]
With the IC memory card 40 loaded in the loading unit 30, the compressed primary color digital image signal output from the memory card control circuit 29 is stored at a predetermined address in the IC memory of the IC memory card 40 via the connector. (Stored). Thus, the storage of the captured image information in the IC memory card 40 is completed.
[0084]
A connector that is electrically connected to the terminal of the IC memory card 40 is installed at the back of the loading unit 30, and is the connector connected to the terminal of the IC memory card 40? Detection means 31 for detecting whether or not is installed.
[0085]
A card transport mechanism (not shown) is installed in the loading unit 30. When the IC memory card 40 is ejected from the loading unit 30, the card transport is performed in accordance with the operation of the eject switch 124. The mechanism operates and the IC memory card 40 is ejected.
[0086]
The IC memory card 40 is a recording medium for storing (recording) an image taken by the imaging apparatus 1 and is a card in which an IC (Integrated Circuit) memory is incorporated. This IC memory has an area for storing the aforementioned image signal (image information) and an area for storing card attribute information. The card attribute information includes, for example, the type of IC memory (for example, static ram, flash memory, etc.), the storage capacity of the IC memory, the access speed, and the like.
[0087]
On the other hand, in the data symbol reading mode, when the second stage of the release switch 121 is turned on, the data symbol reading strobe drive circuit 19 is driven to emit near red light from the light emitting unit 20 of the data symbol reading strobe device. External light is emitted. This near-infrared light is applied to the subject (data symbol 38), and the reflected light is blocked by the second film 65 in the second lens unit 62 of the photographing lens 6, and is reflected by the first lens unit 61 in the first lens unit 61. 1 passes through the first film 64, passes through the optical low-pass filter 7, and reaches the light receiving surface of the CCD 8. In this way, the subject image is formed on the light receiving surface of the CCD 8 (see FIG. 3). Visible light passes through the second lens unit 62 but is in the close-up state. Therefore, a part of the visible light is shielded by the casing and near-infrared light is irradiated. The image that passes through and forms an image on the light receiving surface (imaging surface) becomes dominant.
[0088]
Similarly to the above, charges corresponding to the amount of light corresponding to the subject image (the image of the data symbol 38) are accumulated in each pixel of the CCD 8, and the accumulated charges are sequentially transferred to the CCD signal processing circuit 24. Is input. In the same manner as described above, the red, green, and blue primary color digital image signals of the photographed subject image are temporarily stored at predetermined addresses in the main memory 26 via the CCD signal processing circuit 24 and the A / D converter 25. Is done.
[0089]
Here, as described above, the filter for taking out the red of the CCD 8 is configured to transmit the red component and near-infrared light (wavelength band in the near-infrared region). Although it corresponds to the red component and near infrared light, even if the red component is included in the reading of the data symbol 38, there is substantially no influence. In order to avoid complicated description, the term “red digital image signal” will be used as it is.
[0090]
Next, the address control circuit 23 operates a built-in read address counter based on the clock signal from the control means 11 to read a red digital image signal from a predetermined address in the main memory 26.
[0091]
The read red digital image signal is input to the binarization circuit 36. In the binarization circuit 36, the red digital image signal is compared with a predetermined threshold value (threshold value) and binarized. Thereby, binarized data (binarized signal) is obtained. The binarized data is written at a predetermined address in the RAM 35 in the control means 11.
[0092]
The control means 11 performs predetermined image processing on the binarized data to perform decoding processing (decoding information represented by the data symbol 38). The decoded data (decoding information) obtained by this decoding process is stored (stored) at a predetermined address in the RAM 35. The information represented by the decoded data symbol 38 may be displayed on the display unit 13.
[0093]
Next, the control operation (action) of the control unit 11 of the imaging apparatus 1 will be described.
7 and 8 are flowcharts showing the operation of the control means of the imaging apparatus shown in FIG. 1, respectively. FIG. 8 shows a flowchart (subroutine) showing the operation of the control means when reading data symbols. Has been. Hereinafter, description will be given based on this flowchart.
[0094]
As shown in FIG. 7, first, it is determined whether or not the first step of the release switch 121 is turned on (step S101). If it is determined that the first step of the release switch 121 is turned on, the distance measuring means Then, distance measurement is performed to detect the distance to the subject (step S102).
[0095]
Next, it is determined whether or not the second stage of the release switch 121 is turned on (step S103). If it is determined that the second stage of the release switch 121 is not turned on, the process returns to step S102, and again, step S102 and Step S103 is executed.
[0096]
If it is determined in step S103 that the second stage of the release switch 121 is turned on, the distance to the subject detected in step S102 is determined (step S104), and the distance to the subject exceeds a predetermined value. If so, the process proceeds to step S105 (set to the normal photographing mode), and if the distance to the subject is equal to or smaller than the predetermined value, the process proceeds to step S106 (set to the data symbol reading mode).
[0097]
That is, if the distance to the subject is a distance suitable for normal shooting, the process proceeds to step S105, and normal shooting is performed. If the distance to the object is a distance suitable for reading the data symbol 38, the process proceeds to step S106. Go ahead and read the data symbol.
[0098]
In step S105, as described above, the CCD signal (charge signal) is read from the CCD 8, and the image signal for storage (recording) from the CCD signal, that is, red (R), green (G), and blue (B). A digital image signal is generated (signal processing). Then, the red, green and blue digital image signals are stored (stored) in a predetermined address of the IC memory of the IC memory card 40.
[0099]
In step S106, the subroutine shown in FIG. 8 is called, and as shown in FIG. 8, the data symbol reading strobe drive circuit 19 is driven to emit near-infrared light from the light emitting unit 20 (step S201).
[0100]
Next, an image of the data symbol 38 is captured (step S202). That is, as described above, the CCD signal is read from the CCD 8, and digital image signals of red, green, and blue are generated from the CCD signal, and stored in predetermined addresses of the main memory 26 (step S202).
[0101]
Next, a red digital image signal is read from a predetermined address of the main memory 26, and is compared with a predetermined threshold value (threshold value) to be binarized (step S203). Thereby, binarized data (binarized signal) is obtained, and this binarized data is stored in a predetermined address of the RAM 35 in the control means 11. As described above, the red digital image signal substantially corresponds to near-infrared light.
[0102]
Next, predetermined image processing is performed on the binarized data to perform decoding processing (decoding of information represented by the data symbol 38) (step S204).
[0103]
Next, the decoded data (decoding information) obtained by the decoding process is stored (stored) at a predetermined address in the RAM 35 (step S205), the subroutine is terminated, and the process returns to the main routine shown in FIG. The information represented by the decoded data symbol 38 may be displayed on the display unit 13.
[0104]
After step S105 or step S106, it is determined whether or not the camera is in the shooting mode (step S107).
On the other hand, if the shooting mode is not set, this program is terminated.
[0105]
As described above, according to the imaging apparatus 1, since the imaging lens 6 having the first lens unit 61 and the second lens unit 62 is provided, normal imaging and reading of the data symbol 38 are performed. Can be reliably performed.
[0106]
In particular, the data symbol 38 can be read at a short distance and with a high resolution, thereby increasing the data amount of the data symbol 38 that can be read.
[0107]
Further, since there is no need to provide a mechanism for moving the photographic lens 6, the configuration is simple and the size can be reduced.
[0108]
Further, by reducing the aperture of the first lens unit 61 (decreasing the area), the depth of field in the first lens unit 61 can be increased (widened), thereby more reliably data. The symbol 38 can be read.
[0109]
In addition, the normal shooting mode and the data symbol reading mode are automatically set according to the detected distance to the subject. Can be switched.
[0110]
Further, since the aperture (region) of the second lens unit 62 is larger than the aperture (region) of the first lens unit 61, the influence of near-infrared light during normal photographing is small (substantially not). .
[0111]
Further, since the influence of near-infrared light is large in reading the data symbol 38, the data symbol 38 can be read without any problem.
[0112]
Further, during normal shooting, it is confirmed that there is no unnecessary subject closer to the main subject ("NO" in step S104 in FIG. 7) by distance measurement by the distance measuring means. The image quality of the main subject image is good.
[0113]
Note that during normal shooting, image processing such as adjustment of the Y data level at the center (for example, increasing the gain so as not to be dark) and edge enhancement (preventing blur) may be performed as necessary. it can.
[0114]
In addition, the distance to the subject is three (second range: distance suitable for normal shooting), medium (third range), and small (first range: distance suitable for reading data symbol 38). In step S104 in FIG. 7, it is determined which of the three distances the detected object belongs to, and if it belongs to the middle (third range), a shooting warning (for example, In addition, a display indicating that the distance to the subject is inappropriate may be performed for both normal photographing and reading of the data symbol 38.
[0115]
The imaging apparatus of the present invention has been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each unit is replaced with an arbitrary configuration having the same function. be able to. In addition, any other component may be added to the present invention.
[0116]
In addition, the application of the imaging device of the present invention is not particularly limited. In addition to the electronic camera (digital camera), for example, a camera-equipped cellular phone (including PHS), a portable videophone, a portable personal computer (notebook type). The present invention can be applied to various portable electronic devices (portable terminals) such as personal computers, PDAs, etc., electronic notebooks with cameras, and the like. Furthermore, the present invention can also be applied to electronic devices that are not suitable for carrying, such as laptop personal computers and stationary videophones.
[0117]
【The invention's effect】
As described above, according to the present invention, since the photographing optical system having the first lens unit and the second lens unit is provided, normal photographing and reading of a data symbol (code) are performed. Each can be done reliably.
[0118]
In particular, it is possible to read data symbols at a short distance and with high resolution, thereby increasing the amount of data symbols that can be read.
[0119]
In addition, since it is not necessary to provide a mechanism for moving the photographing optical system, the configuration is simple and the size can be reduced.
[0120]
Further, by reducing the aperture of the first lens unit (decreasing the area), the depth of field in the first lens unit can be increased (widened). Reading can be done.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of an imaging apparatus of the present invention.
2 is a block diagram illustrating a circuit configuration of the imaging apparatus illustrated in FIG. 1;
3 is a cross-sectional view showing an optical system of the imaging apparatus shown in FIG.
4 is a graph showing characteristics of a first film and a second film provided in the photographing lens of the imaging apparatus shown in FIG. 1. FIG.
5 is a cross-sectional view illustrating another configuration example of the imaging lens of the imaging apparatus illustrated in FIG.
FIG. 6 is a plan view showing a configuration example of data symbols.
7 is a flowchart showing the operation of the control means of the imaging apparatus shown in FIG.
8 is a flowchart (subroutine) showing the operation of the control means of the imaging apparatus shown in FIG.
[Explanation of symbols]
1 Imaging device
2 Shooting optical system
51 substrates
52 Mounting part
53 Frame member
54 Spacer
6 Shooting lens
60 Lens body
61 1st lens part
62 Second lens unit
63 Holding part
64 First membrane
65 Second membrane
7 Optical low-pass filter
8 CCD
10 body
11 Control means
12 Operation unit
121 Release switch
124 Eject switch
13 Display section
14 Power supply circuit
15 battery
16 External power circuit
17 Strobe drive circuit for normal shooting
18 Light emitter
19 Strobe drive circuit for reading data symbols
20 Light emitting part
21 CCD drive circuit
22 Synchronization signal generator
23 Address control circuit
24 CCD signal processing circuit
25 A / D converter
26 Main memory
27 Image processing unit
28 Image compression circuit
29 Memory card control circuit
30 loading section
31 Detection means
32 EEPROM
33 Interface circuit
34 External connection terminals
35 RAM
36 Binary circuit
38 data symbols
40 IC memory card
41 Distance measuring unit
42 PSD
43 lenses
44 windows
Steps S101 to S107
Steps S201 to S205

Claims (12)

An imaging optical system for forming an image of a subject and an imaging unit having a light receiving surface arranged at an image forming position by the imaging optical system, and a normal imaging mode for performing normal imaging, and data for reading data symbols An imaging device having a symbol reading mode,
The imaging optical system is used when reading data symbols, and a first lens unit having a first focal length;
A second lens unit that is used in normal photographing, is provided on the outer peripheral side of the first lens unit, and has a second focal length longer than the first focal length;
A first filter provided in the first lens portion and transmitting light in a first wavelength band;
An imaging apparatus comprising: a second filter that is provided in the second lens portion and transmits light in a second wavelength band. The imaging device according to claim 1, wherein the second lens unit has an annular shape. The imaging apparatus according to claim 1, wherein the first lens unit and the second lens unit are integrally formed. The imaging device according to claim 1, wherein a region of the first lens unit is smaller than a region of the second lens unit. The imaging device according to claim 1, wherein an optical axis of the first lens unit and an optical axis of the second lens unit substantially coincide with each other. The imaging device according to claim 1, wherein the first wavelength band is a near infrared region. The imaging device according to claim 1, wherein the second wavelength band is a visible light region. The imaging apparatus according to claim 1, further comprising a strobe device that emits light in the first wavelength band. The imaging apparatus according to claim 8, wherein when reading a data symbol, the strobe device emits light in the first wavelength band. The imaging device according to claim 8, wherein the strobe device is configured by an LED. The imaging apparatus according to claim 10, wherein the light of the first wavelength band is irradiated by continuously lighting the LED. Detection means for detecting the distance to the subject;
12. The apparatus according to claim 1, further comprising: a mode setting unit that selects one of the normal photographing mode and the data symbol reading mode based on a detection result of the detection unit and sets the mode. The imaging device described.

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