JPS592429B2 - Imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an imaging device that has a plurality of rows of photodetectors parallel to the scanning direction and performs interlaced scanning.

FIG. 1 is a diagram showing the configuration of a conventional imaging device, which is composed of a two-dimensional scanner consisting of a combination of a horizontal scanner 1 and a vertical scanner 2, and a photodetector 4 provided at the imaging point of a condensing optical system 3. be.

In this device, the signal light 5 incident from the actual scene is transmitted to the light receiving optical system 6.
A video signal T is guided to a scanner by a photodetector 4 and is amplified by a video amplifier 8 and supplied to an image display 9 . A rotating polygon mirror is often used as the horizontal scanner 1. In this case, the angle at which the reflective surface of the horizontal scanner 1 faces is detected by a photoelectric sensor 10, and the phase signal 11 of each surface obtained by this is detected by the photoelectric sensor 10. Initially, a horizontal synchronizing signal 13 and a vertical synchronizing signal 14 are generated by a synchronizing signal generating circuit 12. Vertical scanner 2 uses this vertical synchronization signal 1
4. FIG. 2 is a diagram showing the configuration of the scanner section. The horizontal scanner is a rotating polygon mirror 16 driven by a motor 15. The angle at which this reflecting surface faces is detected by a photoelectric sensor 10, and the phase of each surface is detected. signal 11
is obtained.

Further, the incident signal light 5 is reflected by the horizontal scanner, then reflected by the vertical scanner 2, and then directed toward the condensing optical system. In such an imaging device, in order to increase the number of scanning lines, a method of arranging a plurality of photodetectors perpendicular to the scanning direction or a method of arranging a plurality of photodetectors in parallel in multiple rows is adopted.

An example is shown in FIG. FIG. 3 is a diagram showing the correspondence between the actual scene and the photodetectors when two rows of photodetectors are arranged in the scanning direction 17. The actual scene 20 and the second row of photodetectors 21
Since the actual scene 22 seen by the user is different, the number of scanning lines is effectively doubled. The video signals obtained by these two rows of photodetectors are, for example, the video signals obtained by the first photodetector in real time, and the video signals obtained by the second row of photodetectors in which the photodetector is outside the field of view. is delayed until the viewing period and is supplied to and displayed on the image display. At this time, the horizontal synchronizing signals to be supplied to the image display include the phase signal of each plane obtained by angle detection of the horizontal scanner and the delay time of the video signal obtained from the second row of photodetectors. What is needed is a superposition of the same amount of delay. Also,
In general, in imaging devices, interlaced scanning is performed to eliminate flicker. In this case, for example, each plane phase signal obtained by angle detection of a horizontal scanner is multiplied by 2, and then 1/(2n ±1), the number of horizontal scans per field is n times, 2
: Obtain a 1-interlace vertical synchronization signal. This vertical synchronization signal generation method is widely used in imaging apparatuses that have one photodetector or one row of photodetectors arranged only in the scanning direction. Therefore, as the synchronizing signal generating circuit 12 in the image pickup apparatus shown in FIG. 1, it is easy to think of a circuit as shown in FIG. 4. This circuit obtains a vertical synchronizing signal 14 by passing each plane phase signal 11 obtained by angle detection of a horizontal scanner through a 2 multiplier 23 and a 1/(2n±1) frequency divider 24. , a delay element 2 that delays each surface phase signal 11 by the time required to sweep one scanning line.
5 and an 0R circuit 26, a horizontal synchronizing signal 13 is obtained. In an imaging device using such a synchronization signal generation circuit, if the photodetectors are arranged so that the actual scene seen by the second row of photodetectors is between the actual scene seen by the first row of photodetectors, the same field can be obtained. However, as shown in FIG. 5, when the first field is scanned, the second field is located in the middle of the actual scene 27 seen by the first row of photodetectors. Since the actual scene 28 seen by the photodetector in the first example when scanning is included, the actual scene 28 seen by the photodetector in the first row when scanning the second field and the actual scene 28 seen by the photodetector in the second row when scanning the first field are included. Actual scene 29 overlaps. In addition, the fifth
In the figure, the broken line arrow represents the vertical scanning direction 30, and the solid line arrow represents the horizontal scanning direction 31. In this way, when the actual scene seen when scanning the first field overlaps with the actual scene seen when scanning the second field, displaying each as separate scanning lines on the image display in order to increase the number of scanning lines will cause the actual scene to include, for example, diagonal straight lines. When taking an image, the image is displayed as shown in FIG. 6, resulting in an unnatural image. In the figure, the shaded area is the area imaged by the first row of photodetectors. In order to solve this drawback, the present invention improves the interlaced scanning method, and will be described in detail below with reference to the drawings.

FIG. 7 shows an embodiment of the present invention, in which an improved synchronization signal generation circuit 32 is a synchronization signal generation circuit of a conventional image pickup apparatus in which photodetectors are arranged in a plurality of rows parallel to the scanning direction.

Hereinafter, a case where two rows of photodetectors are arranged parallel to the scanning direction as shown in FIG. 3 will be described.

FIG. 8 is a block diagram of an improved synchronization signal generation circuit.

First, from each plane phase signal 11, a delay element 25 and an 0R circuit 26 delay the signal by the time required to sweep one scanning line.
A horizontal synchronization signal is created by the combination of On the other hand, the vertical synchronization signal 14 doubles this horizontal synchronization signal 13 and the multiplier 2
After multiplying by 2 by 3, 1/(4n+l) frequency divider 33
/(4n±1). This vertical synchronization signal has a horizontal scanning frequency of n per field.
In other words, this corresponds to scanning in which the number of scanning lines is 2n and 2:1 interlacing is performed. In other words,
This improved synchronization signal generation circuit skillfully realizes scanning with 2n scanning lines per field and 2:1 interlacing in an imaging device in which photodetectors are arranged in two rows parallel to the scanning direction. be able to. FIG. 9 is a configuration diagram of an improved synchronization signal generation circuit when the number of photodetector rows is not two, but m rows in general, and the delay element 25 is m-1.
The difference from FIG. 8 is that the frequency is overlapped and that the frequency divider divides the frequency to 1/(2mn±1).

FIG. 10 is a diagram showing the relationship between the actual scene seen by each photodetector in the imaging device according to the present invention. Due to the function of the improved synchronization signal, the actual scene 27 seen by the first row of photodetectors and the actual scene 27 seen by the first row of photodetectors when scanning the first field are Between the actual scene 29 seen by the two rows of photodetectors, the second
Actual scene 28 seen by the first row of photodetectors when scanning the field
enters.

FIG. 11 shows an image displayed when a real scene including diagonal straight lines is captured by scanning according to the present invention, and a natural image with many scanning lines and a 1:1 correspondence with the real scene is obtained. . In the figure, the shaded area is the area imaged by the first row of photodetectors. Note that the expression "horizontal scanning direction" used in the above explanation is merely for convenience, and is taken as an example of an imaging device such as a television whose scanning lines are approximately parallel to the horizontal direction. do 2
Of the two scanning directions, this refers to the direction with the fastest scanning speed.

Above, the photodetectors are arranged in two rows parallel to the scanning direction, and the ratio is 2:1.
Although the case of interlacing has been described, the present invention is not limited to this, and can be applied to cases where there are three or more rows of photodetectors, and cases other than 2:1 interlacing. As described above, in the scanning method according to the present invention, the actual scene seen by the photodetectors does not overlap due to interlacing, so the actual scene seen by each photodetector can be made to directly correspond to the scanning line of the image display display. A natural-looking image can be obtained even when capturing a real scene that has many scanning lines and includes diagonal straight lines.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional imaging device, Fig. 2 is a block diagram of the scanner section, and Fig. 3 is an imaging system in which two rows of photodetectors are arranged in the scanning direction to double the number of scanning lines. A diagram showing the correspondence between the actual view of the device and the photodetectors, Figure 4 is a configuration diagram of the synchronization signal generation circuit, and Figure 5 is a diagram showing how each photodetector looks in an imaging device having the synchronization signal generation circuit as shown in Figure 4. FIG. 6 is a diagram showing the relationship between actual scenes. FIG. 6 is a diagram showing an image displayed when capturing an actual scene including diagonal straight lines using the scanning method shown in FIG. 5. FIG. 8 is a block diagram of an improved synchronization signal generation circuit according to the present invention, FIG. 9 is a block diagram of an improved synchronization signal when the number of photodetector rows is m, and FIG. Figure 11 is a diagram showing the relationship between the actual scene seen by each photodetector in an imaging device with an improved synchronization signal generation circuit as shown in the figure. It is a figure showing an image displayed when doing so. In the figure, 1 is a horizontal scanner, 2 is a vertical scanner, 3 is a condensing optical system, 4 is a photodetector, 5 is a signal light incident from the actual scene, and 6
1 is a light receiving optical system, 7 is a video signal, 8 is a video amplifier, 9 is an image display, 10 is a photoelectric sensor, 11 is a phase signal for each surface, 12 is a synchronization signal generation circuit, 13 is a horizontal synchronization signal,
14 is a vertical synchronization signal, 15 is a motor, 16 is a rotating polygon mirror, 17 is a horizontal scanning direction, 18 is a two-dimensional scanner, 19 is a first row of photodetectors, and 20 is an actual view seen by the first row of photodetectors. , 21 is the second row of photodetectors, 22 is the actual view seen by the second row of photodetectors, 23 is a 2-multiplier, and 24 is 1/(2n±1)
Frequency divider, 25 is a delay element, 26 is an 0R circuit, 27 is a first
28 is the actual view seen by the first row of photodetectors during the second scan, 29 is the actual view seen by the second row of photodetectors during the first scan. Actual scenery to see, 30
is a vertical scanning direction, 31 is a horizontal scanning direction, 32 is an improved synchronizing signal generation circuit, and 33 is a 1/(4n±1) frequency divider.

Claims (1)

[Claims] 1 A video signal is obtained by a combination of a two-dimensional scanner that scans the field of view of a photodetector in an orthogonal direction, and multiple rows of photodetectors arranged in parallel to the scanning direction on the imaging plane of a light-receiving optical system. In an imaging apparatus, the image signals generated from one photodetector array are displayed in real time, and the image signals generated from the other photodetector array are displayed sequentially using a delay element. The synchronization signal for the first scanning direction component, which has a faster scanning speed among the two scanning directions, is a signal that is synchronized with the scanning period of the scanner that scans the first scanning direction component similarly to the video signal, and a signal that delays the video signal. It is generated by superimposing signals delayed by another delay element having the same delay time as that of the delay element, and the synchronization signal of the second scanning direction component, which has the slower scanning speed of the two orthogonal scanning directions, is the second one. After multiplying the synchronization signal in the first scanning direction by 2, add or subtract 1 to twice the product of the number m of photodetector rows and the number of scans n in the first scanning direction per field. The first signal is generated by dividing the frequency by a reciprocal number, that is, 1/(2mn±1), and this signal drives a scanner that scans in the second scanning direction component. By synchronizing the sweep signals of the second scanning direction components with the synchronization signals of the first and second scanning direction components, the actual scene seen by each photodetector row during scanning of the first field is spaced equally apart without overlapping. An imaging device characterized in that when scanning a second field, it performs interlaced scanning in which the actual scene scanned by each photodetector array is scanned during the scanning of the first field.