JP3125797B2 - Television signal generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television signal generator and, more particularly, to a current system capable of reproducing high-quality and high-definition images with a balanced resolution characteristic from a still image to a moving image. The present invention relates to a generator suitable for generating a television signal having compatibility.

[0002]

2. Description of the Related Art A television signal which is compatible with a current television system and which enables high-quality and high-definition image reproduction with resolution characteristics suitable for a still image without impairing dynamic resolution characteristics is required. As in the case of the telecine image, the current system interlace scanning signal sequence is generated from the image signal sequence of the same frame. The receiver performs the rearrangement operation of the interlaced scanning signal sequence and the scan conversion to the sequential scanning line system by the interpolating operation between frames, thereby realizing the dynamic resolution characteristic suitable for the still image. In addition, signal components frequency-multiplexed with luminance signals, such as color signals and high-definition information, are configured in the form of field line pairs, thereby realizing separation operation of multiplexed signals without crosstalk on the receiver side to achieve high quality and high quality. Attempt to refine.

[0003]

Conventionally, in the generation of the above-mentioned television signal, an image pickup system which uses 525 scanning lines operating at twice the speed of the current television system, and sequentially scans at 60 frames per second is used. Then, an interlaced scanning signal sequence is created from the image signal sequence of the same frame of the progressive scanning obtained by scanning. That is, the signal sequence of the first field and the second field of the interlaced scanning system are generated by the signal sequence of the odd scan line and the signal sequence of the even scan line of the same frame, respectively. For this reason, the imaging system needs to operate twice as fast as the current television system, and the frequency band of the image signal obtained by scanning is doubled, so that the amplifiers need to have broadband characteristics. . Furthermore, in order to convert a signal sequence of progressive scanning of the same frame into a signal sequence of interlaced scanning, the time axis of the signal sequence is changed,
Complicated processing such as time axis expansion is required. As a result,
There is a problem that the cost of the generator for generating the television signal is very high.

An object of the present invention is to provide a television signal generator capable of generating the above-mentioned television signal at extremely low cost.

[0005]

According to the present invention, in order to achieve the above object, an image pickup system having a shutter function constituted by a solid-state image pickup device is used and operated at the same operation speed as that of the current television system. A signal sequence of an interlaced scanning system equivalent to the above-described scan conversion operation from the sequential scanning to the interlaced scanning, which is subjected to a predetermined encoding process to generate a desired television signal. It is.

[0006]

The operation of the progressive scanning system for scan conversion to an interlaced scanning system and the principle of operation of the imaging system of the present invention will be described with reference to FIG.

FIG. 1A shows scan conversion by a conventional progressive scanning image pickup system. With respect to frame signals F1, F2,... Of the progressive scanning system obtained at a cycle of 1/60 second, a signal sequence of the interlaced scanning system is generated from the frame signals of F1, F3,. That is, the odd scanning lines 1, 3, 5,... Of F1, F3,.
Field scan line signal sequence, even scan lines 2, 4, ...
Thus, a signal sequence of the scanning line of the second field is generated. Therefore, in this scan conversion, the frame signal F2,
The information of F4,... Is not used.

On the other hand, in the imaging system according to the present invention, as shown in FIG. 1B, a sequential scanning system obtained by operating the solid-state imaging device by a shutter function with an accumulation period of 1/60 second, which is the same as the sequential scanning system. Of the frame signals corresponding to F1 and F3 are sequentially read by reading the signals of the odd-numbered scanning lines in the first field and the signals of the even-numbered scanning lines in the second field at the operating speed of the interlaced scanning system of the current television system. A signal of an interlaced scanning system equivalent to that of a scanning system is generated.

FIG. 3 shows a FIT (Frame Inter-line Transf).
An example of a configuration using an er) type CCD solid-state imaging device is shown. In the image pickup section, photodiodes for extracting signals of scanning lines corresponding to odd-numbered scanning lines 1, 3,... 2N + 1 and even-numbered scanning lines 2, 4,. Have been. Photodiode arrays of this configuration are arranged by the number of pixels in the horizontal direction, and they are connected to a horizontal CCD in a storage unit. And horizontal C
The output from the CD is amplified by an output amplifier and output as an image signal.

FIG. 4 is a diagram for explaining the operation principle of the FIT type CCD according to the present invention. Note that this is a case where a mechanical shutter is used. Due to the mechanical shutter, image information with a storage time of 1/60 second is stored in the photodiode of the imaging unit. Then, the information of the photodiode corresponding to the odd-numbered scanning line is first transferred to the vertical CCD of the imaging unit by the vertical CCD imaging unit transfer pulse. Then, the information is transferred at high speed to the vertical CCD of the storage unit within the vertical blanking period by the vertical CCD storage unit transfer pulse. When this operation is completed, the information of the photodiode corresponding to the even-numbered scanning line is stored in the vertical CCD of the imaging unit.
Is forwarded to Therefore, at this time, the image information of the odd-numbered scanning lines is captured by the vertical CCD of the storage unit, and the image information of the even-numbered scanning lines is captured by the vertical CCD of the imaging unit. Thereafter, by the normal transfer operation, image information corresponding to one scanning line is transferred to the horizontal CCD during a horizontal blanking period for each line period. By reading out the image information stored in the horizontal CCD, image information corresponding to odd-numbered scanning lines 1, 3,... In the first field of interlaced scanning, and even-numbered scanning lines 2, 3 in the second field.
Image information corresponding to 4,... Can be obtained as output signals. This output signal is equivalent to an interlaced scanning signal generated by scan conversion from the progressive scanning signal sequence shown in FIG.

That is, in the present invention, by using an image pickup system having a configuration in which a solid-state image pickup device and a shutter function are combined, it is possible to realize sequential to interlace scan conversion at extremely low cost.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
Shown in The imaging circuit 1 has, for example, a configuration in which a solid-state imaging device shutter function of a FIT type CCD is combined, and FIG.
The three primary color signals R, G, and B of the interlaced scanning system equivalent to the sequential to interlaced scan conversion as shown in FIG. The YIQ conversion circuit 2 converts the three primary color signals into a luminance signal Y and color difference signals, for example, I and Q, by a predetermined matrix operation.

In the line pair process circuit 4, each of the color difference signals I and Q to be frequency-multiplexed and each component of the luminance signal of the frequency band to be frequency-multiplexed are each of I _p , Q _p and Y _{p in} the form of a field line pair. Create a signal. These signals and the luminance signal Y whose delay has been adjusted by the delay circuit 3
_D performs a predetermined frequency band limitation by the LPF circuits 5, 7, 8 and the HPF circuit 6.

The color difference signals I _pL and Q _pL are _subjected to quadrature amplitude modulation by a color subcarrier f _SC in a modulation circuit 9 to generate a color signal C, as in the current television system.

In the process circuit 10, the desired low-frequency signal Y _L , the medium-luminance signal Y _m , and the chrominance signal C are added, and a predetermined synchronizing signal, burst signal and the like are added to generate a desired television signal. . FIG. 5 shows a one-dimensional signal spectrum of the television signal.

Next, the configuration of each block used in this embodiment will be described.

FIG. 6 shows an embodiment in which the image pickup circuit 1 is composed of a combination of a FIT type CCD image pickup device and a mechanical shutter. The image information obtained by the optical lens 11 is controlled by the mechanical shutter 12 for the time that is accumulated in the solid-state imaging device. The opening / closing operation of this mechanical shutter is controlled by a shutter opening / closing pulse as shown in FIG. Then, in the three primary color separation section 14, the components are separated into three primary color components by a prism or the like, and each is supplied to the FIT type CCD imaging device 15. This F
The IT imaging device 15 is composed of a photodiode, a vertical CCD, a horizontal CCD, and an output amplifier as shown in FIG. 3 described above, and is controlled by a control signal pulse generated in the control signal generating circuit 13 as shown in FIG. The image information is transferred from the photodiode to the imaging unit vertical CCD, the storage unit vertical CCD, and the horizontal CCD to generate a signal sequence of three primary colors R, G, and B of a desired interlaced scanning system.

The image pickup circuit 1 can also be constituted by a combination of a solid-state image pickup device and an electronic shutter, and one embodiment thereof is shown in FIG. The image information that has passed through the optical lens 11 is separated into three primary color components by a three primary color separation unit 14 and supplied to the FIT type CCD imaging device 15. In this imaging device, various operations are controlled by a drive control signal generated in synchronization with a synchronization signal input to the drive circuit 16, and a desired three primary colors R,
G and B signal sequences are generated.

FIG. 8 shows the basic operation of the FIT type CCD image pickup device 15. The contents of the photodiode are cleared by the sweep pulse every frame period, and the image information is accumulated in the photodiode from this time to the time when the reading operation from the photodiode is performed. By odd scan line read signal, the contents of the photodiodes corresponding to the odd scan lines are transferred to the imaging unit vertical CCD at time t _1. Then, by the high-speed transfer mode of the imaging unit transfer pulses, the information transfer operation of the storage unit vertical CCD is performed, information of the time t ₂ in odd-numbered scanning lines are transferred to all storage section vertical CCD. By even scan line read signal at time t _3, the vertical information imaging portion of the photodiode which corresponds to even lines C
Transferred to CD. Therefore, at this time, the vertical C
The CD stores image information equivalent to a signal sequence of one frame obtained by a progressive scanning system of 60 frames per second. After this time, the vertical CC
D performs a transfer operation for each line in a normal transfer mode.
Therefore, in the first field, the storage unit vertical CCD
Is transferred to the horizontal CCD line by line. Thus, at time t _4, the image information is in the manner shown in FIG. And 1
At the end of the field period, all the image information of the odd scanning lines is transferred to the horizontal CCD, and the image information of all the even scanning lines is transferred to the storage unit vertical CCD. Then, by the time t ₅ sweep pulse the contents of the photodiode is cleared, the image information of only the even scan lines in the accumulation unit vertical CCD are accumulated. Then, in the period of the next field, the image information of the odd-numbered scanning lines of the storage section is read out by the same operation in the normal transfer mode.

By repeating the above-described operation for each frame period, an image equivalent to an interlaced scanning signal sequence obtained from the output of this device by scan conversion of a progressive scanning signal sequence of 60 frames per second. A signal can be obtained.

In the basic operation described above, since the read times of the odd-numbered scanning lines and the even-numbered scanning lines are shifted, the accumulation time of the two image information is different.

FIG. 9 is a diagram for explaining the operation when the accumulation time is corrected. In this example, an even-numbered scanning line readout signal is newly generated at a time point Δt (Δt = t ₂ −t ₁ ) away from the sweeping pulse, and stored in the photodiode corresponding to the even-numbered scanning line during the period of Δt. By reading the information indicated by the crosses in the figure, the correction of the accumulation time is realized. The other operations are the same as the basic operations in FIG.

In the operation shown in FIGS. 8 and 9, the vertical CC
Since the transfer in D is performed at the line cycle, there is a problem that the vertical smear becomes large. This vertical smear is shown in FIG.
By performing the operation shown in (1), the reduction can be achieved. That is, the transfer from the imaging unit vertical CCD to the storage unit vertical CCD operates in the high-speed transfer mode within each vertical blanking period, thereby realizing a reduction in vertical smear.

Next, signal processing of the line pair process circuit 4 and a configuration example thereof are shown in FIGS. In the television signal, as shown in FIG. 5, the frequency band of the luminance in band signal Y _m, the color difference signals are frequency-multiplexed as the color signal C. At this time, in order to realize the separation of multiplexed signals without crosstalk on the receiver side, these signals are multiplexed by signal components of a field line pair as shown in FIG. That is, signals having the same signal components are assigned to the signals corresponding to the scanning line 1 of the first field and the scanning line 2 of the second field of the interlaced scanning. As the signal component, for example, an average value of the signals of the scanning lines 1 and 2 is used.

FIG. 12 shows an example of a configuration for generating this signal component. The input signal S is input to the averaging circuit 18 together with the signal _SD delayed by 263 lines by the 263 line delay circuit 17. The averaging circuit 18 performs an arithmetic operation to set the average of the two signals as an output signal S _A (S _A = １ ／ S + ＳS _D ) to generate a signal component of a field line pair. Then, in the selection circuit 19, in accordance with the control signal, the signal S _A in the first field and 263 in the second field.
Selects the output signal S _AD line delay circuit 17 outputs the output signal S _0, such as shown in FIG. 11, to generate a signal component in the form of field lines pairs.

This concludes the description of the first embodiment according to the present invention.

In order to further reduce the cost, it is possible to omit the signal multiplexing function using the field line pair and to configure the television signal in some cases. One embodiment of this case is shown in FIG. Since this operation can be easily understood, a detailed description thereof will be omitted.

The present invention can also be applied to a television signal which realizes high definition as shown in FIG.
In this television signal, a high-definition signal Y _H ′ of a low-frequency component is converted from the luminance high-frequency signal Y _H by a frequency shift operation.
And frequency multiplexing this into the Fukinuki Hole area in the first and third quadrants conjugate to the color signal C in the time and vertical frequency areas.

FIG. 15 shows an overall block diagram of an embodiment for this television signal.

The signal sequence of the three primary colors R, G and B of the interlaced scan obtained from the image pickup circuit 1 is converted into a luminance signal Y and color difference signals I and Q by a matrix operation in a YIQ conversion circuit 2. In this television signal,
The field line pairs shown in FIG. 11 are formed for the color difference signals I and Q, and the field line pairs shown in FIG. 16 are formed for the luminance signals Y _m and Y _H. Therefore, the line pair process circuit 4 and the luminance line pair process circuit 21 generate signals I _P , Q _P , and Y _PP having signal components shown in FIGS.

The signal Y _PP extracts a middle luminance signal Y _m by the BPF circuit 22 and a high luminance signal Y _H by the HPF circuit 23. Then, the signal Y _H is subjected to a carrier suppression amplitude modulation operation by the sub-carrier μ ₀ (μ ₀ = 16 / 7f _SC ) in the frequency shift circuit 24 to generate a high-definition signal Y _H ′.

[0032] In process circuit 26, multiplex these signals, and synchronization signals, burst signals, by adding such mu ₀ phase information, constituting the desired television signal.

[0033]

According to the present invention, an equivalent signal sequence is obtained by generating a signal sequence of an interlaced scanning system from a signal sequence of the same frame of a sequential scanning system by an imaging system using a solid-state imaging device having a shutter function. It is possible to realize a television signal generator having excellent dynamic resolution characteristics and capable of reproducing high-quality and high-definition images at an extremely low cost.

[Brief description of the drawings]

FIG. 1 is an overall block configuration diagram of an embodiment of a television signal generator according to the present invention.

FIG. 2 is a diagram illustrating the principle of an imaging system.

FIG. 3 is a configuration diagram of an FIT type CCD solid-state imaging device used in the present invention.

FIG. 4 is an explanatory diagram of an operation when a mechanical shutter is used.

FIG. 5 is a spectrum of the television signal of the embodiment in FIG. 1;

FIG. 6 is an embodiment of an imaging circuit using a mechanical shutter used in the present invention.

FIG. 7 is an embodiment of an imaging circuit using an electronic shutter.

FIG. 8 is an operation explanatory diagram.

FIG. 9 is an operation explanatory view.

FIG. 10 is an operation explanatory diagram.

FIG. 11 is a configuration diagram of a field line pair.

FIG. 12 shows an embodiment thereof.

FIG. 13 shows another embodiment of the present invention.

FIG. 14 is a spectrum of a television signal for achieving higher definition.

FIG. 15 shows an embodiment according to the present invention.

FIG. 16 shows a field line pair configuration of a luminance signal.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Imaging circuit, 2 ... YIQ conversion circuit, 3 ... Delay circuit, 4
... Line pair process circuit, 5 ... LPF circuit, 6 ... HP
F circuit, 7, 8 LPF circuit, 9 modulation circuit, 10 process circuit, 11 optical lens, 12 mechanical shutter, 13 control signal generation circuit, 14 primary color separation section,
15: FIT type CCD imaging device, 16: drive circuit,
17 ... 263 line delay circuit, 18 ... average circuit, 19 ...
Selection circuit, 20 delay circuit, 21 luminance line pair process circuit, 22 BPF circuit, 23 HPF circuit, 24
... frequency shift circuit, 25 ... delay circuit, 26 ... process circuit.

Continuation of the front page (72) Inventor Naoki Ozawa 1-280 Higashi Koikebo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (56) References JP-A-2-46075 (JP, A) JP-A-3-231593 ( JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H04N 5/225 H04N 5/335 H04N 9/04 H04N 9/64

Claims (1)

(57) [Claims] An image pickup system comprising a solid-state image pickup device having a shutter function combined with a shutter function and operation control of the solid-state image pickup device to form an interface scanning system from a signal sequence of the same frame of a sequential scanning system. sequentially-interlace generates a signal sequence - means for realizing the function of the scan scan conversion, the signal components of the interlaced scanning system Fi - Rudorai
For performing precomposing processing in the form of
Generator of a television signal, characterized in that it comprises a stage.