JPH03238993A - Picture display position automatic adjustment method - Google Patents

Abstract

PURPOSE:To prevent missing of a screen or the like from being caused by making the center of a raster and of a picture coincident with the center of a display screen. CONSTITUTION:A switch 14 is selected to select a signal inputted to a correction pattern signal generating circuit 12 as an external synchronizing signal and a correction pattern signal synchronized with the signal is generated and the correction pattern is displayed on a screen 1. In this case, the color of the displayed correction pattern is, e.g. on green color (G). Then detection elements 2a, 2b and a position detection circuit 3 discriminate the picture display position and a phase adjustment circuit 11 controls the phase of the synchronizing signal inputted to a deflection circuit 9 based on the position data thereby making the phase of the external synchronizing signal with the phase of the blanking line pulse. Thus, the center of the picture and the center of the display screen are matched. Thus, missing of screen of the like is not caused.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for automatically adjusting an image display position on a projection display.

[Conventional technology]

In a projection display, a shift in the display position of the 51iIl image or a shift in convergence may occur due to set movement or temperature drift, resulting in image chipping or deterioration of the l# award. For this reason, a correction pattern based on the retrace pulse is projected, a detector installed outside the screen detects the positional deviation, and the image display position and convergence deviation t-
A device for adjusting has been proposed. Among these, related devices include, for example, Japanese Unexamined Patent Publication No. 65-61590.

[Problem R that the invention attempts to solve]

In the above conventional technology, the center of the image coincides with the center of the screen.

Furthermore, even though consideration has been given to the phase of the raster and the image, there have been problems such as mismatch between the center of the image and the center of one surface, and the display position being shifted, resulting in screen defects.

An object of the present invention is to provide an automatic image display position adjustment method that does not become obsolete due to problems such as screen omission.

(Means for solving IIM) The above object is a means for adjusting the position of the shirasta by a correction pattern based on the retrace pulse from the sounding circuit, and a means for adjusting the phase of the horsemeat current by a correction pattern based on an external synchronization signal. This is achieved by providing a means to do so.

[Effect]

The correction pattern signal generation circuit first outputs a correction beam matched with the phase of the retrace pulse, and aligns the correction pattern with the center of the t-m plane. This causes the center of the raster to match the center of the screen. Next, the correction pattern signal generation circuit outputs a correction pattern matching the phase of the external synchronization signal, and similarly aligns the center of the correction pattern with the center of the screen. As a result, the center of one image coincides with the center of the screen.

With Visa, the center of the raster and the center of the displayed image coincide with the center of the screen, so there will be no screen defects.

〔Example〕

An embodiment of the present invention will be explained below with reference to Fig. a11, Fig. 2, and Fig. 5.

FIG. 81 is a configuration diagram of an image display position automatic adjustment device that implements the multifunction image according to the present invention. 1 is screen, PI,
P is a correction pattern, example 2JL, 2b is a detection element, 3 is a position detection circuit, 4m, 4b, 4c are projection tubes, 5a
- 5b and 5o are deflection yokes, 6a, 6b and 6G are convergence yokes, 7a, 7b and 7G are video circuits, 8 is a convergence circuit, 9 is a deflection circuit, and 10 is a static adjustment circuit.

11 is a phase ms circuit, 12 is a correction pattern signal generation circuit, 15&*15b"15o*14 is a switch, 15.1
6 is a memory.

First, after switching the switch 14t to the deflection circuit 9 and the memory 15@ as shown in FIG. # Generates a correction pattern signal synchronized with the line pulse.

Next, switch one of the switches 15, for example 13a, to the correction pattern signal generation circuit 12 side, and the remaining switch 1
3b and 15a are turned off.

The detection elements 2a and 2b detect the position of the correction pattern projected on the screen 1 by the video circuit 7 and the projection tube 4a, and input the position data to the position detection circuit 5.

Next, the 1st position detection circuit 3 sends a signal to the convergence (8) path 8 to correct it with the correction amount based on this position data, and the convergence circuit 8 causes a correction current to flow through the convergence yoke 6& to locate the center of the correction pattern. Control so that it is centered on the screen.

Since this correction pattern is synchronized with the retrace pulse, this adjustment allows the center of the raster to be aligned with the center of the display screen.

Next, the correction amount is stored in the memory 15, and the switch 15 is turned to perform the same adjustment for the remaining two colors. This makes it possible to simultaneously adjust the convergence shift and the display position shift.

However, the deflection circuit! If the phase of the external synchronization signal and retrace pulse do not match due to horizontal AFC drift, etc.
The display position of the image shifts and one screen is missing.

Therefore, the switch 14t-5 is changed to make the signal input to the correction pattern signal generation circuit 12 the external W55 signal, a correction pattern signal synchronized with this signal is created, and the correction pattern is projected on the screen 1 as described above. do. The color of the correction pattern displayed at this time may be, for example, green (G) only once. Next, the detection elements 2a and 2b and the position detection circuit 3
Based on this position data, the phase adjustment circuit 11 controls the phase of the synchronization signal input to the deflection circuit 9 to match the phase of the external synchronization signal and the retrace pulse. This allows the center of one image to be aligned with the center of the display surface III.

Next, the correction data outputted from the position detection circuit 5 is stored in the memory 16, and a normal image is displayed on the screen 1 by the switch 15, and the adjustment operation is completed.

After the above adjustment operations, adjust the position to the center of the meat surface.

Since the center of the raster and the center of the image match, the meat surface edge o
This eliminates the inconvenience of chipping.

FIG. 2 shows a specific circuit diagram of the phase adjustment circuit 11, in which 17 is a PNP transistor.

18 and 19 are resistors, 20 and 21 are time constant setting capacitors, and 22 and 23 are mono multivibrators.

Next, the operation of this circuit will be explained with reference to the waveform diagram in FIG.

PIP)? The output of the position detection circuit 5 is input to the base of the register 17 through the memory 16. PNP
After the transistor 17 performs a voltage/current conversion operation, a current flows through the collector based on the detected position data of the correction pattern.

Since the output pulse width of the mono multivibrator 22 is determined by the amount of current flowing into the time constant setting capacitor 20, the mono multivibrator 2 of #11
2 is triggered by the falling edge of the input external synchronizing signal shown in FIG. 1(a).

I got a pulse mitt based on the position data of the correction pattern! 1!5 Output the positive polarity pulse shown in Figure (b).

The mono multivibrator 25 of the drop 2 outputs a negative polarity pulse indicated by the third @(oJ) triggered by the falling edge of this output pulse, and inputs this to the f:fmE3@ direction circuit 9 as a synchronizing signal.

As described above, the delayed synchronization signal based on the position data of the correction putter 7 detected by the 1-position detection circuit 5 is supplied to the fan direction circuit 9, so that the phase of the external synchronization signal and the carcass current is controlled.

The above describes the case where the external synchronization signal is of negative polarity, but even when it is positive, the synchronization signal is connected to the input terminal A of the mono multivibrator 22 and the high V HEL t- to the input terminal B of the mono multivibrator 23. This can be done by obtaining the output from the tQ terminal.

〔Effect of the invention〕

As explained above, according to the present invention, the center of the raster and the center of the image coincide with the center of the 3114111 day surface, so that problems such as # missing surface do not occur.

[Brief explanation of drawings]

Figure 1 shows an image display position automatic adjustment device for carrying out the ten-day operation of the present invention! r4 diagram, Figure 2 is a specific circuit diagram of the phase y44 circuit applied to Figure 1, Figure 5 is the phase shown in Figure 2! A! 1 is a diagram of voltage waveforms applied to each part of one circuit. Explanation of symbols 2 & 2b...Detection element, 5...Position detection circuit, 1
1... Phase control circuit, 12... Correction pattern signal generation circuit. Frame Shindai #1 Gei 4- 4 goo for wood tm m-, \

Claims (1)

[Claims] 1. In a projection display in which images projected by red, green, and blue projection tubes are superimposed on a screen, the display position of the projected image on the screen is adjusted to the normal position. An image display position automatic adjustment method that automatically adjusts to the display position, in which a correction pattern signal generated from a correction pattern generation circuit is input to a selected projection tube in synchronization with a retrace pulse generated by a deflection circuit. a first step of projecting the correction pattern onto a screen, a second step of detecting the amount of positional deviation of the projected correction pattern image from the normal position, and storing the detected amount of positional deviation in a memory. A third step in which the center of the corrected pattern image is memorized and a correction signal based on the amount of positional deviation is given to the convergence circuit to match the center of the screen, and the same steps described above are repeated for the remaining two color projection tubes. a fourth step in which the center of the correction pattern image is aligned with the center of the screen; a synchronization signal included in the television signal is used as an external synchronization signal; a fifth step of projecting the correction pattern onto the screen by inputting it to the selected one projection tube; a sixth step of detecting the amount of positional deviation of the projected correction pattern image from the normal position; The amount of positional deviation thus obtained is stored in a memory, and the phase of the synchronization signal input to the deflection circuit is controlled by a phase adjustment circuit based on the amount of positional deviation to align the center of the corrected pattern image with the center of the screen. A method for automatically adjusting an image display position, comprising: a seventh step.