JPH04137870A - Electric still camera device - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the S/N of a picture by placing an analog system signal processing circuit and a digital system signal processing circuit opposite to each other with an optical path inbetween. CONSTITUTION:Printed circuit boards 500, 501 with circuits implementing analog system signal processing mounted thereon, and printed circuit boards 502-504 with circuits implementing digital system signal processing mounted thereon, are installed opposite to each other with various optical system components 108, 110-114. Thus, invasion of noise generated from the digital system signal processing circuit into the analog system signal processing circuit is eliminated. Moreover, since a DC-DC converter 153 is arranged in front of a grip, invasion of noise from the DC-DC converter 153 to the printed circuit boards 500,501 is prevented. Thus, the deterioration in the S/N of a picture is prevented to attain high picture quality processing.

Description

[Detailed description of the invention] [Object of the invention (industrial application field)]
Capture a still image using a solid-state image sensor such as
This invention relates to an improvement in an electronic still camera device that records data in a semiconductor memory.

(Prior Art) As is well known, conventional still cameras for photographing subjects use silver halide film as a recording medium, and after photographing the subject on this film, the film is subjected to chemical processing and developed. , since it becomes possible to view the image of the subject, it is impossible to instantly view the photographed image.

In contrast, in recent years, electrophotographic systems that do not require chemical processing have been developed and commercialized by converting an optical image of a subject into an electrical signal and displaying the image on a television receiver.

As this type of electronic photographic system, there is a still image recording and reproducing system that includes a camera, a reproducing device, a television receiver, and the like.

This still image recording and playback system has the following functions for the camera:
A recording medium such as a tape, disk, or drum made of magnetic material is loaded in the form of a cassette or cartridge to record an image, and then the recording medium is taken out and loaded into a playback machine, and then played back by a television receiver. It is designed to display images.

However, in a still image recording and playback system like the one mentioned above,
Since a magnetic material is used as the recording medium, it is necessary to have a magnetic head and a mechanism for driving the recording medium in order to perform recording and reproduction, which makes the structure large and heavy, and the recording medium This has the disadvantage that the power consumption for driving increases.

Therefore, recently, by using memory cards with built-in semiconductor memory as the recording medium for such still image recording and reproducing systems, it is possible to reduce the size and weight by reducing the magnetic head and mechanical parts, and also to save power. It is being considered. In a still image recording and reproducing system using a semiconductor memory as a recording medium, in addition to ensuring a reduction in size and weight, what is further required is to improve the quality of images.

Here, the S/N ratio of the image is particularly problematic when attempting to improve the quality of the image. In other words, in a still image recording and reproducing system using a memory card as a recording medium, simply a CCD
In addition to A/D (analog/digital) conversion of image signals obtained from other sources and recording them on memory cards,
In order to increase the number of images that can be recorded on one memory card,
A circuit for compressing digitized image signals, an interface circuit between a memory card and a camera, and a CP
Various digital signal processing circuits, such as a central processing unit (U), will be built into the camera.

On the other hand, an analog signal processing circuit is required for the process of subjecting the analog image signal obtained from the CCD to predetermined signal processing and A/D conversion.

In other words, a digital signal processing circuit and an analog signal processing circuit are mixed in the camera.

Therefore, if noise generated in the digital signal processing circuit is mixed into the analog signal processing circuit, the S/N of the image will be reduced.
The ratio will decrease, and high image quality will be hindered.

Here, FIG. 3 shows a signal system of a single-chip imaging unit 100 built into an electronic still camera of a still image recording and reproducing system using a memory card as a recording medium. That is, C
The image signal output from the CDI 14 is supplied to the signal processing circuit 124, where it is subjected to color separation processing and interpolation processing to generate image signals of R, G, and B components. and,
The R, G, and B component image signals are sent to the A/D converter 12.
5a, 125b, and 125c, the terminals 10 are converted into digital image data and constitute the connector section 106.
6a, 106b, and 106c are respectively supplied. Also,
Each motor (not shown) for driving a lens, a diaphragm, etc. (not shown) provided in the lens unit 110 is driven based on a control signal supplied from a signal processing unit 200 (described later) via a terminal 106d. .

Furthermore, the shutter 111 receives a signal from a terminal 106e from the signal processing unit 200 that detects the operation of the first nozzle (not shown).
The shutter driver 126 is driven to open and close based on a control signal supplied via the shutter driver 126 . The CCD 114 also controls the CC based on the control signal supplied from the signal processing unit 200 via the terminal 106f.
By driving the D driver 127, unnecessary charge sweep ratio, vertical and horizontal signal charge transfer, etc. are controlled. Furthermore, the built-in strobe 103 is driven to emit light based on a drive signal supplied from the signal processing unit 200 through the terminal 106g. In addition, the third
In the figure, 108 is a mirror, 112 is an infrared cut filter, and 113 is an optical low-pass filter.

Here, as shown in FIG. 4, the signal processing circuit 124 separates the image signal output from the CCDI 14 into image signals of R, G, and B components in a color separation circuit 128.
The interpolation circuit 129 performs interpolation processing on each of the R, G, and B component image signals, and terminals 130a, 130b, 13
A/D converters 125a, 125b, 125 via 0c
This is what is output to c.

In addition, in the case of a two-plate imaging unit, as shown in FIG.
The RG and B component image signals output from the CCD 117a are separated into R, G, and B component image signals by the color separation circuit 131, and the R, G, and B component image signals are separated from the CCD.
The matrix circuit 132 combines the Y component image signal output from the terminal 117b to generate R, G, and B component image signals.
A/D converters 125a, 125b, 125 via 3c
This is what is output to c. Furthermore, in the case of a three-chip imaging unit, each CCD 120a, 120
The image signals of R, G, and B components output from terminals 34a, 134b, and 134 are output as they are from terminals 34a, 134b, and 134, respectively.
A/D converters 125a, 125b, 125c via c
I am trying to output it to .

Next, FIG. 7 shows the built-in electronic still camera.
The signal system of the signal processing unit 200 described above is shown. That is, each terminal 209 forming the connector section 209 connected to the connector section 106 of the single-chip imaging section 100
a-209g are respectively connected to the respective terminals 106a to 106g of the single-plate imaging unit 100 in a corresponding manner. Among these, Rl supplied to terminals 209a, 209b, and 209c
Each digital image data of G and B components is processed by the process circuit 2.
20. As shown in FIG. 8, this process circuit 220 includes each terminal 209g.

White balance adjustment circuits 220a, 220b, and 220C perform white balance adjustment on the R, G, and B component digital image data supplied to 209b and 209c, respectively, and knee correction circuits 220d and 22
Knee correction is performed using 0e and 22Of, and the γ correction circuit 22
After performing γ correction using 0g, 220h, and 220i, the three digital image data are converted into serial digital image data by a P/S (parallel/serial) conversion circuit 220j, and output from a terminal 220k.

The digital image data output from the process circuit 220 in this manner is supplied to the CPU 221, buffer memory section 222, and buffer memory 223, respectively. The CPU 221 detects the amount of light and focus of the optical image formed on the CCDI 14 based on the output of the input digital image data, and detects whether the optical image is focused or not.
0 and a control signal for driving the shutter 111 and outputs it to the terminals 209d and 209e, as well as each white balance adjustment circuit 220a of the process circuit 220,
220b and 220c, a control signal for odd white balance adjustment is generated. Also, CPU
221 connects the drive signal of the built-in strobe 103 to the terminal 209
Occurs in g.

Further, the CPU 221 causes the timing control circuit 224 to generate a control signal to be supplied to the CCD driver 127 and output it to the terminal 209f, and also generates a timing control signal to be supplied to the process circuit 220.

Here, the buffer memory section 222 and the buffer memory 2
23 has a function of recording one frame of digital image data output from the process circuit 220, and is required together with the addition circuit 225 for the continuous shooting function and multiple exposure function. Note that the CPU 221 extracts various parameters required during continuous shooting and multiple exposure from the parameter setting section 226 based on the input digital image data, and supplies them to the buffer memory section 222.

Then, R and G output from the adder circuit 225.

The digital image data of the B component is sent to the matrix circuit 227.
and is matrix-converted into digital image data of each component of Y, RY, and BY.

Thereafter, the digital image data output from the matrix circuit 227 is supplied to the compression encoding circuit 228, where the data is compressed at a compression rate determined manually or at a compression rate determined by the CPU 221. The compressed digital image data is then transferred to the card I/F (
The signal is supplied via an interface (interface) circuit 229 to a terminal 219a provided on a card holder (not shown) into which a memory card 400 (described later) is attached. Further, this card I/F circuit 229 imports the digital image and audio data read from the memory card 400 into a terminal 219b provided on the card holder,
It has the function of leading out to the outside of the electronic still camera via.

In addition, the audio signal collected by the built-in microphone 230 is sent to an audio processing circuit 231 controlled by the CPU 221.
After being converted into digital audio data, it is led to the terminal 219a via the card I/F circuit 229. Furthermore, the CPU 221 includes an operation section 2.
32 and a signal from a remote control light receiving section 233 that receives an operation signal sent from a remote control operation section (not shown), and the operation state is detected.

Then, the CPU 221 controls the card I based on the signals from the operation section 232 and the remote control light receiving section 233.
/F circuit 229 generates date and time data and adds them to the digital image data.

Furthermore, the CPU 221 reads and detects the header data recorded on the memory card 400 via the card I/F circuit 229 and the terminal 219b, and controls the operation of each part in a programmatic manner based on the intelligent data in the header data. It is something to do. Also, C.P.
The U221 controls the display of the liquid crystal display section 203 and obtains date and time information from a clock circuit 235 driven by a backup battery 234. This signal processing unit 200 is powered by a battery 236 housed in a battery holder (not shown). Note that this battery 236 is used in the single-plate imaging section 100.
It also supplies power to the memory card 400.

Next, FIG. 9 shows the signal system of the memory card 400. That is, when this memory card 400 is attached to the card holder, the terminals 219a,
Terminals 401a and 401 respectively connected to 21.9b
b is provided.

Each of these terminals 401a and 401b is connected via a memory controller 402 to a memory main body 403 containing intelligent data. Then, the digital image and audio data supplied from the signal processing unit 200 to the terminal 401a are recorded in the memory main body 403, and the digital image and audio data recorded in the memory main body 403 are transmitted upon request from the signal processing unit 200. Based on this, reading to the terminal 401b is performed.

Note that this memory card 400 is connected to the signal processing unit 2.
In the deaf state, the signal processing unit 2 is connected to 00.
It operates by receiving power from the battery 236 in 00, but
When taken out from the signal processing unit 200, the recorded contents of the memory main body 403 are protected by a built-in backup battery 404.

The signal system of an electronic still camera using the memory card 400 as a recording medium has been described above, and the internal structure of this electronic still camera is as shown in FIG. That is, 150 in the figure is a printed wiring board, and the signal processing circuit 124 and A/
D converters 125a, 125b, 125c, etc. are provided. A printed wiring board 151 on which the signal processing unit 200 is configured is provided on the back side of the printed wiring board 150.
, 152 are arranged in parallel so as to sandwich the memory card 400 therebetween. In addition, the grip part of the electronic still camera has
The battery 236 and a DC-DC (direct current-direct current) converter 153 that converts the output voltage of the battery 26 to a level required by various circuits configured on the printed wiring board 150 151, 152 are housed. .

However, in the conventional electronic still camera having the above structure, as mentioned earlier, the printed wiring board 150 has a circuit for performing analog signal processing, and a circuit for performing digital signal processing. Arranged printed wiring board 1
51, 152 and the DCDC converter 153 are placed close to each other, so the digital signal processing circuit and the
A problem arises in that the noise generated from the CDC converter 153 leaks into the analog signal processing circuit, degrading the S/N ratio of the image. In particular, the signal processing circuit 124 formed on the printed wiring board 150 is a CCDI
Since it handles minute analog signals output from the 14, it is highly susceptible to external noise, which poses a serious problem.

In order to solve this problem, conventional methods have been considered, such as increasing the distance between boards and parts, or shielding boards and parts, but in both cases the camera itself This resulted in an increase in size and weight, as well as an economical disadvantage, and could not be put to practical use.

(Problems to be Solved by the Invention) As described above, in conventional electronic still cameras, noise generated from the digital signal processing circuit and DC-DC converter leaks into the analog signal processing circuit, resulting in There is a problem that the S/N ratio of

Therefore, this invention was made in consideration of the above-mentioned circumstances, and aims to eliminate noise leakage into analog signal processing circuits, prevent deterioration of the image S/N ratio, and improve image quality. An object of the present invention is to provide an extremely good electronic still camera device that can be made compact and lightweight with a simple configuration.

[Structure of the Invention] (Means for Solving the Problems) An electronic still camera device according to the present invention includes an optical system that guides an optical image of a subject incident through an imaging lens to a solid-state image sensor through predetermined optical system components. An analog signal processing circuit that performs predetermined analog signal processing on the analog image signal output from the solid-state image sensor and converts it into a digital image signal; The target device is a digital signal processing circuit that performs predetermined digital signal processing on a digital image signal and then records it in a semiconductor memory. The analog signal processing circuit and the digital signal processing circuit are arranged at positions opposite to each other across the optical path.

Further, the electronic still camera device according to the present invention includes an optical path that guides an optical image of a subject incident through an imaging lens to a solid-state image sensor through predetermined optical system components, and an analog system that is output from the solid-state image sensor. An analog signal processing circuit that performs predetermined analog signal processing on the image signal and then converts it into a digital image signal, and predetermined digital signal processing on the digital image signal output from the analog signal processing circuit. The target device is a digital signal processing circuit that performs data processing and then records data in a semiconductor memory, and a DC-DC conversion circuit that converts a DC power supply voltage to a desired voltage level. The DC-DC conversion circuit and the analog signal processing circuit are arranged at positions opposite to each other across the optical path.

(Function) According to the above configuration, the distance between the analog signal processing circuit and the digital signal processing circuit can be organically increased, so that the noise generated from the digital signal processing circuit can be reduced. , it is possible to eliminate leakage into analog signal processing circuits, prevent deterioration of the image S/N ratio and achieve high image quality, and is suitable for miniaturization and weight reduction, which is economically advantageous and practical. It can be made to be able to fully serve.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In FIG. 1, the same parts as in FIG. 10 are indicated with the same symbols.

That is, the light incident through the lens unit 110 is directed to the mirror 108. which is provided corresponding to the installation position of the lens unit 110. The light is guided to the CCD 114 via various optical components such as a shutter 111, an infrared cut filter 112, and an optical low-pass filter 113. Also,
The grip part of the electronic still camera device has a DC
- A DC converter 153 and a battery 236 are housed at the rear.

A signal processing circuit 124 and an A/D converter 125a that constitute the single-chip imaging unit 100 are located between the various optical system components and the battery 236.

125b, 125c, etc. are arranged on the printed wiring board 500.
501 are arranged in parallel. In addition, printed wiring boards 500, 50 are mounted on both sides of the various optical system components in the electronic still camera.
On the side opposite to 1, printed wiring boards 502, 503, 504 on which the signal processing unit 200 is configured are arranged in parallel.

According to the configuration of the above embodiment, printed wiring boards 500 and 501 are provided with circuits that perform analog signal processing.
The printed wiring boards 502, 503 and 504 on which circuits for digital signal processing are placed are installed on opposite sides of each other with various optical components in between, so the digital signal processing circuits The noise generated from
It is possible to eliminate leakage into analog signal processing circuits, prevent deterioration of the S/N ratio of images, and improve image quality. Further, since the DC-DC converter 153 is disposed in front of the grip portion, the noise generated from the DC-DC converter 153 is also removed from the printed wiring board 500,
501, and deterioration of the S/N ratio of the image can be prevented. Furthermore, printed wiring boards 500 and 501 and printed wiring boards 502 are placed on both sides with various optical system components in between.
503 and 504, it is suitable for size and weight reduction, is economically advantageous, and is fully usable for practical use. Note that the various optical system components described above are installed in a lens barrel 505 in order to block the leakage of external light, so if this lens barrel 505 is made of a metal material, the shielding effect will be even more effective. .

Further, FIG. 2 shows another embodiment of the present invention, and D
The C-DC converter 153 is placed on the opposite side of the battery 236 across various optical components, and printed wiring boards 502, 503 and 504 are placed between the various optical components and the DC-DC converter 153. It was designed to be installed. According to such a configuration, the distance between the DC-DC converter 153 and the printed wiring boards 500 and 501 can be further increased, so that the analog signal processing circuit configured on the printed wiring boards 500 and 501 can be - It becomes more difficult to be affected by noise generated from the DC converter 153.

Here, by arranging various printed wiring boards 500 to 504 as shown in the above two embodiments, the thickness from the tip of the lens unit 110 to the back of the camera can be reduced, resulting in miniaturization. There is also the advantage of being able to aim for targets.

Furthermore, in the two embodiments described above, the printed wiring board 5
00,501, the signal processing circuit 124 and A/D conversion circuits 125a, 1
25b, 125c, or white balance adjustment circuits 220a, 220b, 220c, =-correction circuits 220d, 220e, 22Of and γ correction circuit 2 shown in FIG.
Part or all of 20g, 220h, 220i, A
/D conversion circuits 125a, 125b 125C when analog processing is performed, these circuits 220a
2201 are also included in the printed wiring boards 500, 501.

Furthermore, in the above embodiment, each printed wiring board 500 to 504
The surface of the CCD 114 and the optical axis incident on the CCD 114 are perpendicular to each other. Although the case of a so-called vertical camera has been described, it goes without saying that the present invention can also be applied to a so-called horizontal camera in which the surface of the printed wiring board and the optical axis are parallel.

It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As detailed above, according to the present invention, noise leakage into the analog signal processing circuit is eliminated, and the S/N of the image is improved.
It is possible to provide an extremely good electronic still camera device that can prevent ratio deterioration and achieve high image quality, and can also be made smaller and lighter with a simple configuration.

[Brief explanation of drawings]

Fig. 1 is a top view showing one embodiment of an electronic still camera device according to the present invention, Fig. 2 is a top view showing another embodiment of the invention, and Figs. 3 to 9 each record a memory card. FIG. 10 is a block diagram showing a signal system of an electronic still camera of a still image recording and reproducing system used as a medium, and is a top view for explaining the problems of the conventional electronic still camera. 100...Single plate type imaging unit, 103 Built-in strobe, 1
06a~106g...terminal, ]08...mirror 110...
...Lens unit, 111...Shutter, 112...
- Infrared cut filter, 113... Optical low pass filter, 114-=CCD, 117 a. 117 b...CCD, 120 a ~ 120
c −= CCD. 124...Signal processing circuit, 125a-125C...
A/D converter, 126... Nyatta driver, 127
... CCD driver 128 ... Color separation circuit, 12
9...Interpolation circuit, 130a to 130C...Terminal, 1
31... Color separation circuit, 132... Matrix circuit,
133a-133cm = terminal, 134a ~ 134c
-...Terminal, 150-152...Printed wiring board, 153...
・DCDC converter, 200... Signal processing unit, 203... Liquid crystal display section, 2098-209g...
Terminal, 211a--Terminal, 219a, 219b--
・Terminal, 220... Process circuit, 220a-220
C...White balance adjustment circuit, 220d~22O
f...Knee correction circuit, 220a-2201...γ correction circuit, 220j...P/S conversion circuit, 220k...
Terminal, 221 CPU, 222 Buffer memory unit, 223 Buffer memory, 224 Timing control circuit, 225 Adding circuit, 226 Parameter setting unit, 227 Matrix circuit, 228...
・Compression encoding circuit, 229...Card I/F circuit, 2
30...Built-in microphone, 231...Audio processing circuit, 232...Operation unit, 233...Remote control light receiving unit, 234...Backup battery, 235
...Clock circuit, 236...Battery, 400...Memory card, 401a, 401b...Terminal, 402...
Memory controller, 403...Memory body, 404
... Backup battery, 500-504... Printed wiring board, 505... Lens barrel. Applicant's Representative Patent Attorney Takehiko Suzue

Claims (2)

[Claims] (1) An optical path that guides the optical image of the subject incident through the imaging lens to the solid-state image sensor through predetermined optical system components, and a predetermined analog signal to the analog image signal output from the solid-state image sensor. After processing, an analog signal processing circuit converts it into a digital image signal, and after performing predetermined digital signal processing on the digital image signal output from this analog signal processing circuit, it is transferred to a semiconductor memory. In an electronic still camera device including a digital signal processing circuit for recording, the analog signal processing circuit and the digital signal processing circuit are installed at positions opposite to each other across the optical path. An electronic still camera device comprising: (2) An optical path that guides the optical image of the subject incident through the imaging lens to the solid-state image sensor through predetermined optical system components, and a predetermined analog signal to the analog image signal output from the solid-state image sensor. After processing, an analog signal processing circuit converts it into a digital image signal, and after performing predetermined digital signal processing on the digital image signal output from this analog signal processing circuit, it is transferred to a semiconductor memory. In an electronic still camera device comprising a digital signal processing circuit for recording and a DC-DC conversion circuit for converting a DC power supply voltage to a desired voltage level, the DC-
An electronic still camera device characterized in that the DC conversion circuit and the analog signal processing circuit are arranged so as to be installed on opposite sides of the optical path.