JP2005223578A - Projection-type video display unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem being a hindrance in rationalization and common use with a general television chassis in a convergence output circuit in a CRT-type projection TV (henceforth, PTV) since it is a special circuit in a television area. <P>SOLUTION: Video image positions on screens of red, green and blue are controlled locally or on the whole so as to overlap colors by installing a color overlap adjusting means controlling compression, enlargement and deformation of a picture by converting a pixel by a digital signal processing. Thus, PTV which does not require the convergence circuit that conventional PTV has is realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to color overlay adjustment of a projection type video display apparatus.

Conventional digital signal processing in a television receiver is a technique for digitizing a video signal and performing processing relating to image quality seen in horizontal / vertical peaking and sharpness, or processing relating to functions seen in multi-screen, IP conversion, and resizing ( For example, see Patent Document 1). In conventional CRT projection TV (hereinafter referred to as PTV), the conventional digital signal processing is to improve the image quality and expand the functions of the video in which Red, Green, and Blue are overlaid on the screen by the convergence circuit. .
Japanese Patent Laid-Open No. 06-292194

  The convergence circuit in the PTV is a special circuit in the television field, and hinders rationalization and common use with a general television chassis.

  By providing color overlay adjustment means that can control the compression, enlargement, and deformation of images by performing pixel conversion using digital signal processing, the video position on the Red, Green, and Blue screens can be controlled locally or entirely. It is possible to perform color superposition. As a result, a PTV that does not require the convergence circuit provided in the conventional PTV is realized.

  The video equipment of the present invention does not require a convergence circuit. As a result, the cost and power consumption of the video equipment can be reduced. Further, it is possible to realize quality improvement by eradicating disturbance factors caused by the convergence circuit, and rationalization by integrating the power deflection substrate of the television chassis with a display device other than the PTV.

(Embodiment 1)
FIG. 1 is a model diagram in a case where convergence (color superposition) adjustment is performed by pixel conversion in signal processing for optical (deflection) distortion due to oblique projection of PTV.

  In FIG. 1A, the raster 3 of the electron beam and the video signal 4 emitted from the Red electron gun 2 projected on the screen 1 without convergence correction are shown by dotted lines. 5 is a deflection yoke (DY), 6 is a Green electron gun, and 7 is a Blue electron gun.

  Conventionally, the correction waveform generated by the digital convergence circuit for the optical distortion of Red, Green, and Blue projected on the screen 1 caused by the CRT attachment (tilt) or lens aberration is generated by an amplification circuit (convergence output circuit). Converted to a correction current flowing in the convergence yoke (CY), a magnetic field is formed in the CRT by the current flowing in the CY, the direction of electrons in the CRT is changed, the raster 3 on the tube surface (screen 1) is deformed, Red, By controlling the three colors of Green and Blue arbitrarily (generating an arbitrary correction waveform by digital convergence), video signals of Red, Green, and Blue are overlapped to obtain a normal image.

  On the other hand, FIG. 1B shows the state of the video signal 4 corrected by the pixel conversion (compression, enlargement, deformation) in the digital signal processing by a solid line, and the raster 3 is not deformed (conventional convergence circuit). In other words, the red, green, and blue convergence (color superimposition) on the screen 1 matches.

  In the case of Red, as shown in FIG. 1A, since the projection is performed on the screen 1 from the left side, the projection distance on the right side is longer than the left side of the screen 1, and the trapezoidal distortion is caused by the difference in magnification that is proportional to the projection distance. . This is a typical distortion in PTV, and it can occur similarly in the case of Blue projected from the right side to the screen 1. In order to correct such trapezoidal distortion, a normal image can be obtained for the screen 1 by performing “compression” and “enlargement” processing as shown in FIG.

  The information on the compression, enlargement, and deformation location on the screen is the coordinate axis of the memory for storing the video signal (digital data) in the video signal processing unit (LSI) (time with respect to the synchronization signal) and parameters such as the compression / enlargement ratio such as EEPROM Even if the video signal processing unit (LSI) is reset due to power OFF / ON or the like, it is retained by performing pixel conversion processing based on the stored (read) parameters.

  For example, when performing pixel conversion to enlargement magnification P at time T from the synchronization signal, the parameters (T, P) = (t1, p1), (t2, p2)... Are stored in the EEPROM. For the video signal (digital data) read out along the synchronization signal and stored in the memory, processing for reading out the area of time T and setting it to the enlargement magnification P is performed before and after the line memory or before and after the pixel. The pixel-converted data is stored in the memory, or the red, green, and blue video signals (digital data) after pixel conversion are D / A converted at any time by the synchronization signal, so that the convergence (color overlap) is performed on the screen. Project the matching video.

  In addition, by changing parameters (T, P) using an IIC controller or microcomputer and sending data to an LSI register, it is possible to perform pixel conversion processing for compression, enlargement, and deformation at any location on the screen. Pixel conversion convergence (color superposition) adjustment by signal processing can be realized.

(Embodiment 2)
FIG. 2 is a model diagram in the case where enlargement, compression, and the like of the image of one frame or one field are performed simultaneously. Horizontal expansion / compression is realized by pixel conversion using a line memory.

  When enlarging the pixel area A stored in the line memory and compressing the pixel area B, t as a reference axis is set, and 0 to t and t to T on the time axis are assigned to A and B signal processing, respectively. . In A, enlargement is performed by resizing processing from 2 pixels to 3 pixels, and from 4 pixels to 5 pixels, and in B, compression is performed by thinning processing.

  On the other hand, as shown in FIG. 3, the vertical expansion / compression of the image is performed by using a frame memory, setting τ as a reference, and dividing it into an expansion area of time axis 0 to τ and a compression area of τ to T. Pixel conversion processing is performed in the area t1, t2,... In the area, and in the compression area τ + t1, τ + t2,. When the enlargement magnification of t1 is α, the enlargement magnification of tp (0 <tp <τ) is (α−tp * (α / τ)), and m pixels are formed from n pixels according to the enlargement magnification of each block. Process. When the compression ratio of T is β, the compression ratio of tq (τ <tq <T) is (β * (tq−τ) / (T−τ)), and thinning processing is performed according to the compression ratio of each block. Perform compression processing.

  These horizontal and vertical enlargement / compression processes include filter processing to smoothly connect the information before and after the pixel (one line before and after the frame memory) and right and left (before and after the line memory). It suppresses image quality degradation due to enlargement / compression.

  FIG. 4 is a model diagram of a scanning line in an optical (deflection) distortion and an image projected on the screen 8. In order to obtain a regular image by performing color superposition by moving arbitrary pixels, it is realized by rearranging the pixels using line memory and frame memory, that is, by locally performing the same processing as in enlargement / compression .

  By assigning t, T, τ, A, B, etc. in the process described above as coefficients and parameters, the enlargement / compression ratio can be freely changed, and color superposition adjustment is realized.

(Embodiment 3)
FIG. 5 is a model diagram when the user adjusts color superposition in a PTV having a pixel conversion convergence adjustment circuit. As shown in FIG. 5, the remote control code is used to switch the variable range (SIZE), position (POS), and adjustment (ADJ). ) To adjust the color overlap of Red, Green, and Blue on the screen by the operation of SIZE / POS / ADJ.

  Regarding the SIZE control, the OSD area that displays the variable range on the screen corresponds to the pixel conversion target area: SIZE (H, L) of the memory that stores the video signal (digital data), and the POS control is the center of the OSD, that is, the pixel The center of the conversion target area: POS (x, y). The ADJ control is for changing (compressing, enlarging, and deforming) the video in the area in the vertical and horizontal directions, and POS (x, y) = (0, 0), SIZE (H, L ) Area +1 to the right and up +1, the data in the memory is moved so that the SIZE (H, L) image centered at POS (x, y) = (1, 1) is obtained. The boundary between the pixel conversion target region and the non-target region is smoothly connected by the filter process.

  FIG. 6 is a model diagram in the case of color superposition using a portable mobile camera or video camera device. As shown in FIG. 6, parameters for capturing the image displayed on the screen with a portable mobile camera or a video camera device, and adjusting the convergence by the pixel conversion process from the amount of red, green, or blue convergence (color overlap). Is calculated, and the parameter conversion feedback is automatically fed back to the digital signal processing circuit (data transmission to the LSI register).

  Regarding the parameter calculated from the deviation amount of convergence (color overlap), the variable amount that cancels the deviation is converted into a numerical value (data). For example, when pixel conversion is performed with the enlargement ratio P at time T from the synchronization signal, the offset data (α, P2)... For the parameters (T, P) = (t1, p1), (t2, p2). ...) is added, or a coefficient is set and added, and processing for setting (T, P) = (t1, p1 + α), (t2, p2 + β)... is performed before and after the line memory or before and after the pixel. . The pixel-converted data is stored in the memory, or the red, green, and blue video signals after pixel conversion are D / A converted at any time by the synchronization signal, thereby correcting the deviation of convergence (color overlap) on the screen. The projected image is projected. The above processing is automatically repeated until the amount of deviation converges, and the adjusted parameters are automatically replaced with the data before adjustment of the EEPROM.

  In the first to third embodiments, the CRT projection TV (PTV) has been described as an example. However, the projection display image display device is not limited to the PTV.

  In recent years, pixel conversion technology is in a category that can be processed by a general-purpose DSP, and optical distortion excluding convergence correction in PTV has been improved year by year. It is speculated that it may be used for TV.

Model diagram showing convergence adjustment in Embodiment 1 of the present invention Model diagram showing enlargement / compression of an image according to the second embodiment of the present invention Model diagram showing enlargement / compression of an image according to the second embodiment of the present invention Image model diagram according to Embodiment 2 of the present invention Model diagram showing user adjustment in Embodiment 3 of the present invention Model diagram showing user adjustment in Embodiment 3 of the present invention

Explanation of symbols

1 Screen 2 Red electron gun 3 Raster 4 Video signal 5 Deflection yoke (DY)
6 Green electron gun 7 Blue electron gun 8 Screen

Claims (3)

A video apparatus provided with color superposition adjusting means for compressing, enlarging, and deforming an image projected by a projection-type video display device by performing pixel conversion by signal processing and adjusting color superposition of Red, Green, and Blue. The video equipment according to claim 1, wherein the color superimposing adjustment unit simultaneously performs color compression by performing compression, enlargement, and deformation of an image by signal processing within one frame or one field. The video equipment according to claim 1, wherein the color overlay adjusting unit accepts a manual operation.

Images