IMAGE SIGNAL PROCESSING APPARATUS

Abstract

According to preferred embodiments of the present invention, an image signal processing apparatus for converting an interlace signal which creates a frame image by alternately displaying an odd field and an even field on a single screen into a progressive signal, includes a line memory for storing the interlace signal, a writing/reading portion for writing/reading the interlace signal into/from the line memory, a signal generation portion for generating a prescribed signal, a selector for selectively outputting the interlace signal from the line memory or the prescribed signal from the signal generation portion, and a controller for controlling signal selection by the selector. The controller controls the selector such that, when the odd field of the interlace signal is being read from the line memory, the interlace signal is outputted from the line memory to odd lines of a progressive signal to be converted and the prescribed signal is outputted from the signal generation portion to even lines of the progressive signal, and when the even field of the interlace signal is being read from the line memory, the interlace signal is outputted from the line memory to even lines of the progressive signal and the prescribed signal is outputted from the signal generation portion to odd lines of the progressive signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the present invention are shown by way of example, and not limitation, in the accompanying figures, in which:

FIG. 1 is a block diagram showing an image signal processing circuit according to an embodiment of the present invention;

FIG. 2 is a timing chart showing the operation of the image signal processing circuit shown in FIG. 1;

FIGS. 3 to 5 show various images created by image signal processing circuits according to embodiments of the present invention;

FIGS. 6 to 12 show various image signal processing circuits according to another embodiments of the present invention; and

FIG. 13 is a block diagram showing an image signal processing circuit as a related art.

Claims

1. An image signal processing apparatus for converting an interlace signal which creates a frame image by alternately displaying an odd field and an even field on a single screen into a progressive signal, the apparatus comprising: a line memory for storing the interlace signal;a writing/reading portion for writing/reading the interlace signal into/from the line memory;a signal generation portion for generating a prescribed signal;a selector for selectively outputting the interlace signal from the line memory or the prescribed signal from the signal generation portion; anda controller for controlling signal selection by the selector,wherein the controller controls the selector such that, when the odd field of the interlace signal is being read from the line memory, the interlace signal is outputted from the line memory to odd lines of a progressive signal to be converted and the prescribed signal is outputted from the signal generation portion to even lines of the progressive signal, and when the even field of the interlace signal is being read from the line memory, the interlace signal is outputted from the line memory to even lines of the progressive signal and the prescribed signal is outputted from the signal generation portion to odd lines of the progressive signal.

2. The image signal processing apparatus as recited in claim 1, wherein the signal generation portion generates a black image signal showing black or color close to black as the prescribed signal, andwherein the controller controls the selector such that, when the odd field or the even field of the interlace signal is being read, the black image signal is outputted from the signal generation portion to all of even lines or odd lines of the progressive signal, respectively.

3. The image signal processing apparatus as recited in claim 1, wherein the signal generation portion generates a white image signal showing white or color close to white as the prescribed signal, andwherein the controller controls the selector such that, when the odd field or the even field of the interlace signal is being read, the white image signal is outputted from the signal generation portion to all of even lines or odd lines of the progressive signal, respectively.

4. The image signal processing apparatus as recited in claim 1, wherein the signal generation portion includes a black image signal generation portion which generates a black image signal showing black or color close to black as the prescribed signal, and a white image signal generation portion which generates a white image signal showing white or color close to white as the prescribed signal,wherein the controller controls the selector such that, when the odd field or the even field of the interface signal is being read, the black image signal and the white image signal are alternately outputted from the signal generation portion to a single even horizontal line and a single horizontal odd line of the progressive signal.

5. The image signal processing apparatus as recited in claim 1, wherein the signal generation portion includes a black image signal generation portion which generates a black image signal showing black or color close to black as the prescribed signal, and a white image signal generation portion which generates a white image signal showing white or color close to white as the prescribed signal,wherein the controller controls the selector such that, when the odd field or the even field of the interlace signal is being read, the black image signal and the white image signal are alternately outputted from the signal generation portion to every single pixel of each single horizontal even line or every single pixel of each single horizontal odd line of the progressive signal, respectively.

6. The image signal processing apparatus as recited in claim 1, wherein the signal generation portion generates an intermediate color signal showing color between white and black as the prescribed signal;wherein the controller controls the selector such that, when the odd field or the even field of the interlace signal is being read, the intermediate color image signal is outputted from the signal generation portion to all of even lines or odd lines of the progressive signal, respectively.

7. The image signal processing apparatus as recited in claim 1, wherein the signal generation portion generates a color signal showing color other than white, black and an intermediate color between white and black as the prescribed signal;wherein the controller controls the selector such that, when the odd field or the even field of the interlace signal is being read, the color image signal is outputted from the signal generation portion to all of even lines or odd lines of the progressive signal, respectively.

8. An image signal processing apparatus for converting an interlace signal which creates a frame image by alternately displaying an odd field and an even field on a single screen into a progressive signal, the apparatus comprising: a first line memory for storing the interlace signal;a writing/reading portion for writing/reading the interlace signal into/from the first line memory;an input-output converter having an input-output comparative table, the converter being configured to receive the interlace signal from the first line memory, convert brightness level of the interlace signal with reference to the input-output comparative table into a converted signal and output the converted signal,a second line memory for storing the converted signal from the input-output converter;a selector for selectively outputting the interlace signal from the first line memory or the converted signal from the second line memory; anda controller for controlling signal selection by the selector,wherein the controller controls the selector such that, when the odd field of the interlace signal is being read from the first line memory, the interlace signal is outputted from the first line memory to odd lines of a progressive signal to be converted and the converted signal is outputted from the second line memory to even lines of the progressive signal, and when the even field of the interlace signal is being read from the first line memory, the interlace signal is outputted from the first line memory to even lines of the progressive signal and the converted signal is outputted from the second line memory to odd lines of the progressive signal.

9. The image signal processing apparatus as recited in claim 1, further comprising a gain adjuster disposed between the line memory and the selector, the gain adjuster being configured to increase brightness level of the interlace signal from the line memory to output the interlace signal to the selector.

10. An image signal processing apparatus for converting an interlace signal which creates a frame image by alternately displaying an odd field and an even field on a single screen into a progressive signal, the apparatus comprising: a line memory for storing the interlace signal;a writing/reading portion for writing/reading the interlace signal into/from the line memory;an avenge picture level calculator for calculating an average value of a brightness level of the interlace signal from the line memory;a selector for selectively outputting the interlace signal from the line memory or the signal from the average picture level calculator; anda controller for controlling signal selection by the selector,wherein the controller controls the selector such that, when the odd field of the interlace signal is being read from the line memory, the interlace signal is outputted from the line memory to odd lines of a progressive signal to be converted and the signal from the average picture level calculator is outputted to even lines of the progressive signal, and when the even field of the interlace signal is being read from the line memory, the interlace signal is outputted from the line memory to even lines of the progressive signal and the signal from the average picture level calculator is outputted to odd lines of the progressive signal.

11. The image signal processing apparatus as recited in claim 10, wherein the average picture level calculator obtains an average value of a brightness of a single horizontal line of the interlace signal.

12. The image signal processing apparatus as recited in claim 1, wherein the average picture level calculator obtains an average value of brightness of every several pixels of a single horizontal line of the interlace signal, the calculator being provided with a plurality of registers for holding the average values, and wherein the controller controls the selector such that signals from the plurality of registers are outputted selectively.