JPH02125572A - Digital electronic still camera - Google Patents

Abstract

PURPOSE:To attain multi-function of a digital electronic still camera and to improve the added value by adding a timer function to apply pickup automatically at a desired time interval or after a desired time elapses. CONSTITUTION:For example, a pushbutton of a data input device 41 is depressed to select the timer mode. The timer mode is roughly classified into the following 3 modes. A 1st mode is a conventional self timer mode. A 2nd mode is a consecutive shot mode at a prescribed time interval and a 3rd is the aperiodic consecutive shot mode. For example, in the case of the 1st mode, a timer operation time is stored in a memory circuit 51 for timer. A system controller 42 counts a clock signal supplied from a clock signal generating circuit 54 and when the count corresponding to the timer operating time is finished, each circuit from an image sensor 2 to a memory 33 is driven to apply pickup.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Fields of Application] The present invention digitally processes a video signal obtained by imaging with an image sensor, and electronically records a still surface image.
The present invention relates to a digital electronic still camera configured to reproduce images, and more particularly to a digital electronic still camera configured to automatically take photographs at desired time intervals or after a preset desired time.

[Prior Art] A conventional electronic still camera processes a video signal obtained by an image sensor using analog signal processing. That is, C.C.
The video signal read from an image sensor such as D is subjected to T correction and white balance adjustment, and a matrix circuit generates a luminance signal and a color difference signal.Then, these luminance signals and color difference signals are passed through a low-pass filter of a predetermined band. Only the necessary frequency components are obtained, FM modulated, and recorded on a magnetic recording medium.

However, in such conventional electronic still cameras, the process from imaging to recording is performed by analog signal processing, and there are limits to image quality improvement due to variations in the characteristics of the matrix circuit and low-pass filter.

On the other hand, in recent years, digital electronic still cameras have been proposed as a solution to the above-mentioned problems, and are gradually becoming popular.

Various proposals have been made regarding the digital electronic still camera, and an outline thereof will be explained with reference to FIGS. 2 to 4.

That is, in FIG. 2, a color image sensor 2 consisting of a CCD receives an optical image of a subject that enters through an optical system 1 having a photographing lens, an aperture, a shutter, etc., and performs a color image by well-known horizontal and vertical readout scanning. Color signals R, G, and B are read out from each pixel of the image sensor 2, and the A/D converter 3 converts them into 8-bit (i.e., 2
It is converted into a digital signal indicating the sub-levels (56 levels). Note that in the cell array of the color image sensor 2, as shown in FIGS. 3(a) and 3(b), the ratio of the green (G) part to the red (R) and blue<8) part is 2:2. A color filter having a ratio of 1:1 is provided to form a pixel, and by performing horizontal scanning readout for each row, the color signals R, G,
B is output.

These digitized color signals R, G, and B are input to a matrix circuit consisting of a high-range luminance signal generation circuit 4, a low-range luminance signal generation circuit 5, color difference signal generation circuits 6 and 7, and an adder 9, and the luminance signals are Y and color difference signals R-Y and B-Y are formed.

The high-band luminance signal generation circuit 4 calculates the following equation (1
), by performing the calculations in (2), the high-frequency luminance signal YH
occurs.

YH=0.25(B+Rd)+0.25(G+Gd)
・ ・ ・ (1) YH=0.25 (R
+Bd) +0.25 (G+Gd) ・
・ ・ (2) In the above equation, when the color signals from the image sensor 1 currently undergoing horizontal scanning readout are the blue signal B and the green signal G, the above equation (1) is calculated, and the output signal is When is the red signal R and the green signal [, :, the above equation (2) is calculated.

The high-frequency luminance signal YH is shown in FIG. 4(a) (shown as 0
~4.2λ)) It is supplied to the digital low-pass filter 8 having a passband of 4Z, and also to the adder [ ].

The low-band luminance signal generation circuit 5 calculates the following equation (3) based on the color signals Rd, Gd, Bti delayed by one horizontal period (]FI) and the color signals R, G, B obtained by the current horizontal scanning readout. , (4) to generate the low-range luminance signal YL.

YL = 0.11 (B-G) + 0.30 (Rd-Gd)
+G...(3)YL=0.11(Bd+G
d) +0.30(R-G)+G (4) When the color signals from the image sensor 1, which is currently undergoing horizontal scanning readout, are the blue signal B and the green signal G, the above formula is applied. The calculation in (3) is performed, and when the output signals are the red signal R and the green signal G, the calculation in equation (4) is performed.

Then, the low frequency luminance signal YL is subtracted from the high frequency luminance signal YH in the adder 9, and the luminance signal YL-YH generated by the subtraction processing is 0 to 0.0 as shown in FIG. 4(b).
The signal is supplied to a digital low-pass filter 10 having a passband of 7 MHz, and output as a luminance signal YL.

The color difference signal generation circuit 6 calculates the following equation (5) based on the color signals Rd, Gd, and Bd delayed by one horizontal period (IH) and the color signals R, G, and B from the current horizontal scanning readout. A color difference signal RY is generated.

R-Y=Q, 7 (R-G) -0,11(Bd-Gd
,) ...(5) And this color difference signal R-Y
is supplied to a digital low-pass filter 11 having a pass band of 0 to 0.7 MHz as shown in FIG. 4(c).

The color difference signal generation circuit 7 calculates the following equation (6) based on each color signal Rd, Gd, Bd delayed by one horizontal scanning period (1i4) and each color signal R, G, B obtained by the current horizontal scanning readout. Due to the scarcity, a color difference signal BY is generated.

B-Y=0.89 (B-G) -0,30(Rd-G
tj) ...(6) And this color difference signal B
-Y is also 0 to 0.7 (not shown in Figure 4(C))! , lHz.

Further, in the adder 13, the luminance signals YH and Ye (!:) from the digital low-pass filters 8 and 10 are added, and as shown in FIG. A luminance signal Y containing the following is formed.

The luminance signal Y and the color difference signals R-Y and B-Y of the predetermined frequency components generated in this way are manually input to the data compression circuit 14 to reduce the number of bits, thereby reducing the storage capacity and compressing the data. The luminance signal Y and the color difference signals RY and BY are outputted to the connector 16 via the input/output interface 15.

The luminance signal Y and the color difference signals R-Y and B-Y are sent to a memory card 1 equipped with a semiconductor memory (static RAM).
8, and the memory card 18
Recording and playback are made possible by attaching an input/output interface 17 connected to the connector 16 to the connector 16.

The memory card 18 can record, for example, 26 frames worth of surface image data, and can be edited and deleted at will, making it extremely convenient.

“Problems to be Solved by the Invention” By the way, in the digital electronic still camera,
It does not have a timer function, and therefore, when taking pictures while watching a subject, the photographer has to operate the shutter each time, which is very inconvenient. Furthermore, it is not possible to automatically take a photograph after a desired time has elapsed, and when such photography is necessary, the photographer must always be aware of the passage of time. Also, there were times when I missed a photo opportunity due to carelessness or sudden requirements.

For this reason, it has been desired to add a timer function to digital electronic still cameras that can automatically take pictures on a regular or irregular basis.

The present invention has been made in view of the above-mentioned circumstances, and its objects are as follows: 1. by adding a timer function to automatically take photographs at a desired time interval or after a desired time has elapsed;
The objective is to increase the functionality and added value of digital electronic still cameras.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a digital electronic still camera with a timer memory circuit for storing timer photography data, a clock signal generation circuit for generating a clock signal, and the above-mentioned. This system is equipped with a system controller or the like that counts clock signals and automatically performs photographing based on preset desired time intervals or timer photographing data such as the number of photographs to be taken.

[Function] In the present invention having such a configuration, for example, the data manual means provided in the digital electronic still camera is operated to store the photographing time interval, irregular photographing time, and number of photographed images in the timer memory circuit. Stores timer data such as The clock signals generated within the set time are counted and photos are automatically taken when the set time is reached, so photos can be automatically taken at desired time intervals or at irregular time intervals. This makes it possible to further enhance the functionality of digital electronic still cameras.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. Note that FIG. 1 is a circuit diagram of a digital electronic still camera to which the present invention is applied, and the same or corresponding parts as in FIG. 2 are designated by the same reference numerals.

First, the configuration will be explained with reference to FIG. 1. A CCD image sensor 2 equipped with color filters arranged as shown in FIG. Color signals R (red), G (green), and B (blue) of each pixel are output by vertical scanning readout.

These color signals R, G, and B are amplified to a desired level by a preprocessing circuit 21, and then subjected to gamma correction, white balance correction, and the like.

The A/D converter 3 converts the color signals R, G, and B into, for example, 8-bit digital signals.

The signal processing circuit 23 includes a first buffer memory that temporally stores these digitized signals for one frame.
(not shown) as well as a high frequency luminance signal generating circuit 4, a low frequency luminance signal generating circuit 5, a color difference signal generating circuit 6.7 and an adder 9 similar to those shown in FIG. a signal R, stored in the first buffer memory;
Based on G and B, a high frequency luminance signal YH, a low frequency luminance signal YL, and color difference signals RY and BY are generated. That is, the signal processing circuit 23 performs the calculations described in equations (1) to (6) above, and generates the color difference signals R-Y, B-Y and YL-YH.
It generates a luminance signal.

The data compression circuit 14 includes a luminance signal Y1 and a color difference signal R-YSB.
- This is provided to reduce the number of bits of Y and to reduce the storage capacity of a memory cartridge, which will be described later. Then, the data-compressed luminance signal Y and color difference signal RY,
B-Y is output to the connector 16 via the input/output interface 15.

On the other hand, a memory cartridge 31 is connected to the connector 16 and outputs a luminance signal Y1 and a color difference signal RY.

It is configured to store B-Y and other information. That is, the memory cartridge 31 includes an interface 32, a semiconductor memory (for example, static RAM) 3
3. Power batch leak (not shown), etc.

By connecting the memory cartridge 31 to the connector 16, the luminance signal Y1 and the color difference signal R-YSB-Y are supplied via the interface 32 during photographing.
is stored in the surface image data area A of the semiconductor memory 33.

Furthermore, during playback, the stored surface image data can be read out and displayed on a display (not shown) by operating a system controller 41, which will be described later.

In addition to the surface image data storage area A, the semiconductor memory 33 is allocated a surface image information area B that stores storage capacity, storage contents, battery expiration date, etc., making it easy to manage the surface image data and the memory cartridge 31. It is designed to. Further, the semiconductor memory 33 is provided with a timer information area C for storing timer information, which stores information necessary for timer and timer functions.

The data manual device 41 is mounted (pushed) at an easily operated position on the side of the case of the electronic still camera, and is configured such that a timer mode or the like can be selected by a push button or the like.

The system controller 42 (control circuit) is a microcontroller that centrally manages the operation timing for taking pictures, storing them in the memory cartridge 31, reading them from the memory cartridge 31, and using a timer function.
It consists of a processor, etc.

The timer memory circuit 51 is connected to the system controller 4
2 via the address bus 52 and data bus 53, and the clock signal generation circuit 54 generates a clock signal to be sent to the system controller 421.2. :Supply.

Next, the circuit operation of the digital electronic still camera configured as described above will be explained.

First, when a shutter release button (not shown) is pressed to instruct photographing, the optical system 1 is set to the optimum photographing state, and the system controller 42 instructs the image sensor 2 to start scanning readout.

The color signals R, G, and B from each pixel outputted in time series by the scanning readout are amplified to a desired level in a preprocessing circuit 21, and subjected to gamma correction, white balance correction, and the like. Then, it is converted into a digital signal by the A/D converter 3, and the R, G, B signals corresponding to the pixel array are converted into digital signals.
The color signal is supplied to the signal processing circuit 23.

In the signal processing circuit 23, the calculations described in equations (1) to (6) above are performed, and the luminance signal Y and the color difference signal RY,
B-Y is generated, and the data compression circuit 14 performs data compression on the luminance signal Y and the color difference signals R-Y and B-Y as described above.

During imaging, the interface 14 is controlled by the system controller 42 to output the surface image data to the connector 16 side, and the compressed surface image data is transferred to the memory card 3 via the connector 16 and the interface 32.
It is stored in the surface image data area A of No. 3.

In this embodiment, the circuit operations from photographing to storage are performed as described above, and the timer function operates as described below. In this case, the timer mode is selected by operating, for example, a push button on the data manual device 41, and the following three types of timer modes are possible.

The first is a normal self-timer mode, in which the waiting time setting can be varied.

The second type is continuous photography at predetermined time intervals, and the data input circuit 41 manually inputs the start time, the time width of the repetition period, and the number of times of photography.

The third mode is an irregular continuous shooting mode, which is carried out by inputting the desired time (or year, month, and day) of shooting one by one through the data input circuit 41.

In the timer mode, a large number of shots may be required, so in that case, the time at which the user wants to take pictures is stored in the memory information area C of the memory 33.

The types of timer modes have been explained above, and the circuit operation is performed as follows.

That is, when the timer mode is selected by the data input circuit 41, the data is transmitted to the system controller 42, and in the case of the first mode, the timer operating time is stored in the timer memory circuit 51. From this point on,
The system controller 42 has a clock signal generation circuit 54
When the count corresponding to the timer operation time is completed, each circuit from the image sensor 2 to the memory 33 is driven in the same manner as described above to take a photograph.

When the second timer mode is selected, the system controller 42 causes the timer memory circuit 51 to store data such as the start time, the photographing repetition period (time width), and the number of times of photographing. And system controller 4
2 counts clock signals in the same manner as described above until the set photographing is completed, and photographs are taken in the same manner as described above at each repetition period.

When the third timer mode is selected, the time at which an irregular photograph is desired is input and stored in the timer memory circuit 51 by the system controller 42. Then, the system controller 42 counts the number of signals in the same manner as described above, and takes a photograph in the same manner as described above at each set interval.

As described above, the digital electronic still camera of this embodiment can perform manual photography and automatic photography using the timer function.

Note that in the digital electronic still camera, the following measures have been taken to reduce power consumption.

That is, during the time waiting period, the system controller 42, timer memory circuit 51, and clock signal generation circuit 54 are energized to monitor the set time. Immediately before the set time, each circuit is energized to be in an operable state, and after one shooting is completed, the power to circuits other than those required for monitoring is cut off again. According to this configuration, even if a large number of shots are taken using the timer function, there is no unnecessary power consumption during waiting time.
It is possible to extend the life of the battery.

Furthermore, the system controller 42, etc. is
(OS) may be configured with transistors.

In this embodiment, the color filters provided on the image sensor are red (R) and blue (B).

A green (G) mosaic filter is used, and the frequency bands of the luminance signal and color difference signal are defined in accordance with the case of a specific number of pixels, but the invention is not limited to this, and for example, a striped filter array , red (R), blue (B),
The present invention can also be applied to other imaging methods in setting the complementary color filter of green (G), the appropriate number of pixels, and the frequency bands of the luminance signal and color difference signal.

Effects of the Invention As explained above, according to the digital electronic still camera of the present invention, the shooting time interval and the number of shooting repetitions are stored in the timer memory circuit, and the clock signal is counted by the system controller and set in advance. Since the camera is configured to automatically take pictures based on the timer data set, it becomes easy to perform watching shooting and continuous automatic shooting, thereby increasing the functionality and adding value of digital electronic still cameras. Can be done.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a digital electronic still camera showing an embodiment of the present invention; Fig. 2 is a circuit diagram showing an example of a conventional digital electronic still camera; Fig. 3 is an explanatory diagram showing the arrangement of color filters: FIG. 4 is a characteristic curve diagram showing the frequency characteristics of the digital filter. Reference numeral 1 in the figure; optical system 2; image sensor 3; A/D converter 14: data compression circuit 15; interface 16: connector 23: signal processing circuit 31 = memory cartridge 32; interface 33/memory card 41 ; data input device 42; system controller 43; data path 51; timer memory circuit 54: clock signal generation circuit. Figure (a) (b) Figure

Claims (1)

[Claims] A surface imaging device, an A/D converter that converts a video signal read out from the solid-state imaging device into a digital signal, and storing surface image data in a solid-state memory based on the digital signal. Among digital electronic still cameras, this digital electronic still camera is characterized by being equipped with an automatic release with a timer function.