JPH09266580A - Linear sensor camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the sensitivity of color signal of a camera and to limit the color information quantity of a luminance signal by driving respective linear sensors or partial sensors in different scanning cycles or corresponding to different operating clocks. SOLUTION: The optical image of an object from a lens 1 is split by a half mirror 5 and made incident on a monochromatic linear sensor 4 and a color linear sensor 3. A basic clock from a synchronism generating part 18 inside a memory device 17 is supplied to a synchronous coupling part 6 of a camera part 2, and a synchronizing signal for driving the sensors 3 and 4 is reproduced. This synchronizing signal is supplied to a color synchronism generation circuit 7 and a monochromatic synchronism generation circuit 8, and processing for changing monochromatic and color scanning cycles is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear sensor camera used for color imaging of a high-speed moving object in a boat race, a horse race, a bicycle race, an athletics competition, and the like.

[0002]

2. Description of the Related Art As a method for obtaining a color image by combining an image sensor, (1) an image is separated into three primary colors of GBR by a spectroscopic optical system and a color separation filter, and three corresponding three colors are used. Method of obtaining GBR signal with monochrome sensor, (2) Method of obtaining GBR signal on image sensor and GBR signal with integrated color sensor, (3) Method of obtaining GBR filter on image sensor There is a method in which one color sensor and one monochrome sensor are combined to obtain color information from the color sensor and luminance information from the monochrome sensor. Methods using a plurality of sensors include the methods (1) and (3).
Since the method (1) is a method of calculating a GBR signal obtained from each sensor to obtain a luminance signal, it is necessary to drive each sensor in the same scanning cycle. Similarly, each sensor in (3) needs to be driven in the same scanning cycle, which is a sensor driving method that has been generally used from the past.

FIG. 3 shows an example of a conventional sensor drive circuit for the above method (3). In the figure, 1 is a lens, 4
Reference numeral 0 is a camera unit, and 17 is a memory device. Camera section 40
The color linear sensor 3 and the monochrome linear sensor 4 used in the same are the same synchronization signal generating circuit 41.
Driven by the sensor drive clock signal 44 and the sensor drive scanning signal 45 of the same cycle from, the color signals are output from the respective sensors 3 and 4 via the GBR output circuit and the luminance signals are output via the Y output circuit 16. In the memory unit 17, the respective color signals and luminance signals are stored in the GBR signal writing circuit 2
1, digitized by the Y signal writing circuit 22, and recorded in the GBR memory 26 and the Y memory 27 which are image memories. The camera unit 40 and the memory device 17 operate synchronously by the synchronous coupling circuit 6. Further, when writing video information to the image memory, the purpose of using the memory efficiently and the fact that the human eye has a low resolution for color signals make it practical even if the color information is limited to some extent. For the reason that there is no problem, it is common practice to thin out the color signals obtained from the color sensor and write them in the memory.

As a method of thinning out a color image signal obtained from the color sensor 3, the sampling frequency after A / D is 1/2, 1/3, 1 with respect to the clock frequency which determines the scanning cycle of the linear sensor. / 4 etc. and reduce the image information to be recorded in the memory to every 1 pixel, every 2 pixels or every 3 pixels, so-called thinning method in the main scanning direction (pixel direction of linear sensor), and There is a thinning method for writing an image in the orthogonal direction, that is, every other scanning line, every two scanning lines, every three scanning lines, or the like. Alternatively, a method of using them together is generally used.

In the case of the example of the conventional system shown in FIG. 3, the synchronizing circuit 4 is provided to the Y address controller 25 which generates a write signal for writing the monochrome video signal 14 into the Y memory 27.
GBR that supplies the clock signal for memory writing obtained from 2 as it is and writes the color video signal to the memory
To the address controller 24, the clock for memory writing and the scanning signal obtained from the synchronizing circuit 42 are used by being divided into 1/2 by the writing clock frequency dividing circuit 23 and the writing period frequency dividing circuit 43, respectively. As a result, as for the monochrome signal, the video information obtained from the linear sensor camera is written into the image memory 27 for all pixels, but the color signal is halved for the main scanning and ½ for the sub scanning, that is, for monochrome. As a result, image information is thinned out to one quarter and written in the image memory 26.

Next, in the output stage, the video information of the GBR memory 26 and the Y memory 27 is read out by the synchronization generator 3 for reading.
The read sync signal from the control unit 1 controls the GBR read address controller 32 and the Y read address controller 33 to read the data at a sync cycle that matches the TV signal.
With the luminance signal from 7, the composite color video signal is produced by the encoder circuit 29 and output from the video output terminal 30.
Of course, since the color signal is 1/4 of the information with respect to the luminance signal, it is necessary to read the color signal with respect to the luminance signal at a frequency of 1/2 in both horizontal and vertical directions.

The above operation will be described with reference to the timing chart of FIG. FIG. 4A is a conceptual diagram of a monochrome video signal waveform, and Hm is a scanning number given for convenience of description. (B) shows the timing of writing the video signal of (a) to the image memory 27, and shows that all the image information is written to the Y memory 27 without missing in the Hm number because it is synchronized with the video. ing. (G) is a conceptual diagram of a color video signal waveform, and Hc is a scanning number given for convenience of description. (H) shows the timing of writing the video signal of (g) to the image memory 26. Since it is the timing of writing the video every other scan, the image information should be thinned to half and written to the GBR memory 26. Is shown.

Next, attention will be paid to sampling within one scanning period. (A ') and (g') show enlarged views of (a) and (g), respectively, and (e) and (i) show respective sampling clocks. Vm indicates the number of pixels of the monochrome sensor, and the clock (e) is 1024 per scanning period.
It is a memory write clock corresponding to a pixel and indicates that all pixel data of a monochrome signal is written to the Y memory. Vc indicates the number of pixels of the color sensor,
The clock (i) is a memory writing clock corresponding to 512 pixels, which is one half of Vc = 1024 pixels per scanning period, and all pixel data of the color signal is halved and written to the GBR memory. Is shown.

Thinned Hc = 1, Hc = 3, Hc = 5
The image of the scan number such as Hc = 1023 is not used and is discarded. As described above, in the conventional method, the thinned-out video signal is treated only as a redundant signal, and is treated as a completely useless signal.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to effectively use a video signal, which has not been effectively used in the conventional sensor driving method and digitizing method, as a level signal of the video signal.

[0011]

In order to achieve the above object, the present invention is designed to drive each or a part of a plurality of linear sensors to be combined with different scanning periods or operation clocks. The monochrome sensor used in the linear sensor camera of the present invention is, for example, 1
When the color sensor is driven in different scanning cycles such as 2 ms cycle, the light receiving time of the color sensor becomes twice as long as that of the monochrome sensor. Therefore, the obtained signal level is the same as that of the monochrome sensor in the same scanning cycle. It will be double the level. Further, in this way, one scan of the color sensor signal is obtained for two scans of the monochrome sensor signal, and the thinning processing in the subsequent stage is not required, so the circuit is simplified and the color sensor All the obtained video signals can be effectively used as video information. In this way, in order to increase the level of the video signal obtained from the color linear sensor, that is, to improve the sensitivity of the color signal of the linear sensor camera, and to efficiently use the memory, the sampling cycle of the color information is changed from the luminance information to the sampling cycle Both of the purpose of lowering the amount of information by lowering the information amount can be realized at the same time by driving the respective linear sensors at different scanning cycles.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing one embodiment of the present invention. Reference numeral 1 is a lens, 2 is a camera unit, and 17 is a memory device. The optical image of the subject from the lens 1 is divided by the half mirror 5, one of which is the monochrome linear sensor 4
And the other is incident on the color linear sensor 3. The basic clock 38 from the synchronization generator 18 in the memory device 17 is supplied to the synchronous coupling circuit 6 of the camera unit 2.
The sync signal driving the sensors 3 and 4 is reproduced. The sync signal is supplied to the color sync generation circuit 7 and the monochrome sync generation circuit 8, and here, processing for changing the scanning cycle for monochrome and for color is performed. For example, the color scanning signal 10 has a period of 2 ms, and the monochrome scanning signal 13 has a period of 1 m.
s period. Since the period of the scanning signal period is the time when the sensor receives light, the color linear sensor 3 receives the light for twice as long as the monochrome linear sensor 4, and the obtained video signal level is twice the 1 ms period.

The color clock signal 9 is a clock having a frequency substantially equal to the color scanning signal 10 divided by the number of pixels of the color linear sensor (including the effective video period and the blanking period), and also for monochrome. Clock signal 1
Similarly, since 2 is a clock having a frequency of a value obtained by dividing the monochrome scanning signal 13 by the number of pixels of the monochrome linear sensor, if the number of pixels of the color and monochrome sensors is the same, the clock frequency for monochrome is more than that for color. That's twice as expensive. If the number of pixels is different between color and monochrome, the sensor may be driven by a clock signal of each frequency divided by the number of pixels based on the scanning cycle.

GBR color signal 11 and Y signal 1 obtained from the color linear sensor 3 and the monochrome linear sensor 4
4 is a GBR output circuit 15 and a Y output circuit 16 respectively.
Through the GBR writing circuit 21 and the Y writing circuit 22 of the memory device 17 to the GBR memory 26 and the Y memory 27. The timing and address for writing to the memory are the scanning signal 3 from the synchronous coupling circuit 6 of the camera.
A timing clock is generated by the GBR synchronizing circuit 19, the Y synchronizing circuit 20, and the clock frequency dividing circuit 23 from 9 and the basic clock 38, and the GBR address controller 24 and the Y address controller 25 control the memory to perform the write operation.

The clock frequency dividing circuit 23 is the GBR synchronizing circuit 1.
The GBR write clock 34 obtained from No. 9 is divided into two, and the number of write pixels in the main scanning direction is halved. Color linear sensor 3
If the number of pixels of each GBR is 1024, all image information can be captured if the effective period of the image is sampled at 1024. However, since color signals are generally thinned out and captured, here, 1024 The sampling clock is frequency-divided by the clock frequency dividing circuit 23 to be a write clock so as to capture 512 pixels.

In the sub-scanning direction, since the color signal in the camera head 2 is already half the scanning period of the monochrome signal, the timing of writing the color signal in the GBR memory 26 is every 2 ms. The cycle of writing the monochrome signal to the Y memory 27 is every 1 ms, and the amount of information in the sub-scanning direction to be written to the memory is one half of the monochrome signal for the color signal.

For example, if the memory size of the Y memory 27 is 1
If the number is 024 × 1024 dots, the GBR memory 26
Is written by dividing the GBR writing clock 34 in the main scanning direction by two and scanning in the sub-scanning direction in the camera 2 at a half cycle, the memory size is 512 × 5.
It may be 12 dots. 1024 x 102 in Y memory
51 to the GBR memory while writing the information for 4 dots
Information of 2 × 512 dots is written.
That is, it means that the color information is one half each in the main and sub scanning directions and the information amount is one quarter of the monochrome information. The output stage is the same as that of the conventional example, and therefore its explanation is omitted.

Next, the above operation will be described with reference to the timing chart of FIG. FIG. 2A is a conceptual diagram of a monochrome video signal waveform, and Hm is a scanning number added for convenience of description. (B) shows the timing of writing the video signal of (a) to the image memory, and shows that all the image information is written to the Y memory 27 without loss in the Hm number because it is synchronized with the video signal. ing. (C) is a conceptual diagram of a color video signal waveform when the scanning cycle is twice that of monochrome, and Hc is a scanning number given for convenience of description. (D) shows the timing of writing the video signal of (c) to the image memory, and shows that all the image information is written to the GBR memory 26 without loss in the Hc number because it is synchronized with the video. There is. Here, since the scanning period tm = 1 ms for the monochrome signal and tc = 2 ms for the color signal, the image information amount per unit time is written, for example, when the scanning number of Hm = 1022 is Hc = 511. As you can see, it's halved.

Next, attention will be paid to sampling within one scanning period. (A ') and (c') show enlarged views of (a) and (c), respectively, and (e) and (f) show respective sampling clocks. Vm indicates the number of pixels of the monochrome sensor, and the clock (e) is 1024 per scanning period.
It is a memory write clock corresponding to a pixel and indicates that all pixel data of a monochrome signal is written to the Y memory. Vc indicates the number of pixels of the color sensor,
The clock (f) is a memory writing clock corresponding to 512 pixels, which is one half of Vc = 1024 pixels per scanning period, and all pixel data of the color signal is halved and written to the GBR memory. Is shown.

In this embodiment, the color sensor and the monochrome sensor having the same number of pixels are used. However, if the color sensor is selected to have a half of the number of pixels of the monochrome sensor, the GBR writing is performed. It is not necessary to thin the clock 34 for use by half. In this embodiment,
Although the color linear sensor in which one monochrome and one color linear sensor are combined has been described, even if the visible light sensor and the infrared sensor are combined and the infrared sensor is subjected to the sensor driving method applied to the color sensor described above. Good, focusing on the G channel of the color linear sensor camera composed of three linear sensors of GBR, which has high resolution and modulation characteristic of the optical system such as lens and prism, and the linear of other B and R channels. The sensor driving method applied to the color sensor described above may be performed on the sensor.

[0021]

According to the present invention, the object of increasing the level of a video signal obtained from a color linear sensor, that is, improving the sensitivity of the color signal of a linear sensor camera, and the sampling rate of the color signal with respect to the luminance signal. , And the purpose of limiting the amount of color information can be realized at the same time.

[Brief description of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a timing chart of an image and sampling for explaining the present invention.

FIG. 3 is a block diagram showing a conventional example.

FIG. 4 is a timing chart of an image and sampling for explaining a conventional example.

[Explanation of symbols]

1 ... Lens, 2 ... Camera section, 3 ... Color linear sensor, 4 ... Monochrome linear sensor, 5 ... Half mirror,
6 ... Synchronous coupling circuit, 7 ... Color synchronous generation circuit, 8 ...
・ Monochrome sync generation circuit, 9 ... Color clock, 1
0 ... Color scanning signal, 11 ... GBR color signal, 1
2 ... Monochrome clock, 13 ... Monochrome scanning signal, 14 ... Y signal, 15 ... GBR output circuit, 6 ... Y
Output circuit, 17 ... Memory device, 18 ... Synchronization generation unit, 1
9 ... GBR synchronous circuit, 20 ... Y synchronous circuit, 21 ... G
BR writing circuit, 22 ... Y writing circuit, 23 ... Clock frequency dividing circuit, 24 ... GBR address controller, 25 ... Y address controller, 26 ... GBR memory, 27 ... Y memory , 28 ... Color difference encoder, 29
... Encoder, 30 ... TV color video signal output terminal,
31 ... Read synchronization generating circuit, 32 ... GBR read address controller, 33 ... Y read address controller, 34 ... GBR write clock, 35 ...
..Y writing clock, 36 ... GBR writing scanning,
37 ... Y writing scan, 38 ... Basic clock, 39 ...
Scan signal, 40 ... Conventional camera section, 41 ... Synchronous generation circuit, 42 ... Synchronous reproduction circuit, 43 ... Scan frequency dividing circuit, 4
4 ... Sensor drive clock signal, 45 ... Sensor drive scan signal

Claims (5)

[Claims] 1. A linear sensor camera provided with a combination of a plurality of linear sensors as an image sensor,
A linear sensor camera, characterized in that each sensor or a part of the sensors is driven with different scanning periods or different operation clocks. 2. The linear sensor camera according to claim 1, wherein the linear sensor camera has a sensitive wavelength region, spectral sensitivity, sensitivity, operable clock frequency, light receiving element size,
A linear sensor camera, which is configured by combining linear sensors having different light receiving element pitches or all or some of the number of elements. 3. An image sensor including at least one monochrome linear sensor, an image sensor including at least one color linear sensor, an optical system for forming an optical image on the image sensor, and the image sensor. And a luminance information recording means and a color information recording means for recording the output of the image pickup device. The image pickup device driving means includes an image pickup device including the monochrome linear sensor and the color A linear sensor camera, characterized in that each of the image pickup devices composed of a linear sensor is configured to operate at a different scanning cycle or a different operation clock. 4. The linear sensor camera according to claim 3, wherein a scanning cycle or an operating clock of the image sensor including the color linear sensor is equal to or less than half of a scanning cycle or an operating clock of the image sensor including the monochrome linear sensor. Is a linear sensor camera. 5. The linear sensor camera according to claim 4, wherein a recording capacity of the color information recording means is 1/2 or less of a recording capacity of the luminance information recording means.