JP2527020B2 - Digital TV signal recorder - Google Patents

Description

TECHNICAL FIELD The present invention relates to a digital television signal recording device using a semiconductor memory as a recording medium.

[Conventional technology]

The conventional digital television signal recording device has a small memory capacity of 1 to 4 fields, and the read address is automatically generated by the reference signal.

[Problems to be Solved by the Invention] In the conventional technology described above, the memory capacity is 1 to 4
The number of fields is small, and since the read address was automatically generated from the reference signal, the desired image stored in this image memory can be read at any time while writing the image in the image memory. There was a problem that I could not do it.

[Means for solving the problem]

In order to explain such a problem, the present invention relates to an A / D converter that encodes an analog video signal and an image storage device that stores an image of one field or more of an output video signal of this A / D converter. A read field address input terminal for inputting a desired read field address, a read field address input section for holding a read address for each field input from the read field address input terminal and generating a read control signal, and a read field address input section for each field. A write field address generator that generates a write address and a write control signal, and a read address that generates the address of each pixel in one field by using the read field address output from the read field address input unit as an input and gives it to the image memory. Generator and write 1 the write field address output from the field address generator as an input
A write address generator that generates the address of each pixel in the field and gives it to the image memory, and a D / A that decodes the encoded video signal read from the image memory into an analog signal.
A converter is provided.

[Action]

The digital television signal recording apparatus according to the present invention can simultaneously read out an image and write an image independently.

〔Example〕

FIG. 1 is a system diagram showing an embodiment of a digital television signal recording apparatus according to the present invention. In the figure, 1 is an A / D that encodes an analog video signal to obtain a coded video signal.
A converter 2 is an image memory for storing an image of one field or more of the output video signal of the A / D converter 1, and 3 is a D for decoding the encoded video signal read from the image memory into an analog signal. A / A converter, 4 is a sync signal adder, and 5 is a write field address a output from a write field address generator 7 to be described later as an input to generate an address of each pixel in one field and give it to the image memory 2. A write address generator 6 receives a read field address b output from a read field address input section 8 to be described later as an input to generate an address of each pixel in one field and gives it to the image memory 2;
Reference numeral 7 is a write field address generator for generating a write field address a and a write control signal c in field units, and 8 is a read field address input for holding a read field address in a field unit inputted from the outside and generating a read control signal d. 9 is a read field address input terminal, and 10 is a clock generator.

In FIG. 1, when an image is recorded, the write field address a generated by the write field address generator 7 is applied as the write address, the write control signal c is supplied to the image memory 2 and the write address generator 5 is supplied. give. When reproducing an image, the read field address input terminal 9 is used as a read address.
The read field address e input from is held in the read field address input section 8 and the read control signal d is given to the image memory 2 and the address generator 6. The write field address and the read field address generated at this time are independent of each other.

The input address video signal is converted into an 8-bit digital signal by the A / D converter 1 and recorded in the image memory 2. When the read address generator 6 gives an address to the image storage device 2, a digital signal is output from the image storage device 2. The digital signal is converted by the D / A converter 3 into an address signal, and then the sync signal adder 4 Add a sync signal with and output to the outside.

Fig. 2 shows that the input images are in alphabetical order, such as A, B, C, D, E, ..., O, P, Q ,. Change, write field address, 0,1,2,3, ..., 10,0,1, ... The correspondence between the field address 12 fields after the start of and the recorded image is shown. As shown in the figure, address 0 corresponds to image L, address 1 corresponds to image B, ..., Address 10 corresponds to image K.

If a value of 1 is input from the read field address input terminal 9 12 fields after the start of recording, the image L is read. If the value of 5 is input from the terminal 9, the image E is read. In this way, while writing an image, it is possible to simultaneously read out any image written at that time.

〔The invention's effect〕

As described above, the present invention has an address generator for generating an address of each pixel in one field independently for reading and writing, and further stores an image storing a predetermined number of fields for each field. It has a memory and a read field address input terminal for inputting a desired read field address.

Therefore, even while an image is being written in the image memory, by inputting a desired read field address from the read field address input terminal, an arbitrary image can be selected from the plurality of images stored in the image memory. Can be read.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a digital television signal recording apparatus according to the present invention, and FIG. 2 is an image state diagram for explaining the operation thereof. 1 ... A / D converter, 2 ... image storage device, 3 ... D / A converter, 4 ... sync signal adder, 5 ... write address generator, 6 ... readout address generator, 7 ...... Write field address generator, 8 …… Read field address input section, 9 …… Read field address input terminal, 10 …… Clock generator.

Claims (1)

(57) [Claims] 1. An A / D converter that encodes an analog video signal to obtain a coded video signal, and an image storage device that stores an image of one field or more of an output video signal of the A / D converter.
A read field address input terminal for inputting a desired read field address, a read field address input section for holding a read address for each field input from the read field address input terminal and generating a read control signal, and a write address for each field And a write field address generator for generating a write control signal, and a read address generator for generating the address of each pixel in one field by inputting the read field address output from the read field address input section and giving it to the image memory. And the write field address output from the write field address generator as input
A writing address generator for generating an address of each pixel in the field and giving it to the image memory, and a D / A converter for decoding an encoded video signal read from the image memory into an analog signal are provided. Digital TV signal recorder.