JPS59104884A - Automatic static convergence adjusting device - Google Patents

Abstract

PURPOSE:To adjust automatically the shift in the static convergence by forming a point image for adjusting red, green and blue color on a photo detector installed at a prescribed location at the outside of an effective plane of a projecting screen to detect a position of the point image for adjusting each color on the photo detector. CONSTITUTION:When a red pattern signal is generated from a pattern signal generator 10, this signal drives a red picture tube 1R by a picture tube driver 7 to output a red pattern signal, and this signal light is made incident to the photo detector installed at a prescribed position at the outside of an effective plane of a transmission type screen 9 via a lens 4 and a sub-mirror 11. A device 12 outputs, e.g., an incident red pattern signal by photoelectric-converting the signal, an operating device 13 photoelectric-converts and outputs a red pattern signal light and operates positional shift on the surface of the device 12 of the red pattern signal light. Further, horizontal and vertical static convergence adjusting devices 14H, 14V generate suitable correcting signals EH, EV to adjust horizontal and vertical shift for adjusting automatically the shift.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a television image projection device for enlarging and projecting a television image projected on a picture tube onto an Eli screen using a lens, and more particularly, The monochromatic image projected on the video tube is combined into a color image using two dichroic mirrors, and this color image is enlarged onto the screen using a lens.3 In a television image projection device that projects images on a screen, static convergence adjustment is automatically performed. The present invention relates to a device for carrying out this process.

Conventional configuration and problems There are several known types of television image projection devices that enlarge and project a television image projected on a quadrant onto a screen using a lens. 1
One type of television image projection apparatus is as shown in FIG.

First, its configuration will be explained.

With the green picture tube 1G in the center, the red picture tube 1R and the blue picture tube IB'i, their face brakes) 2R,
2G and 2B are arranged in a T-shape so that they are adjacent to each other at right angles, and three video tubes 1R and 1G.

In a rectangular parallelepiped space surrounded by face plates 2R, 2G, and 2B of 1B, a dichroic mirror 3R for red reflection and a dichroic mirror 3Blx for blue reflection are arranged so as to cross each other in a letter shape. A lens 4 is arranged on the optical axis of the green picture tube 1G. Regarding the dichroic ink mirror 3H for red reflection, the red picture tube 1R and the green picture tube 1G are mirror images, and the dichroic ink mirror 3B for blue reflection has a mirror image relationship.
Regarding this, the blue picture tube 1B and the green picture tube 1G are mirror images. The monochromatic images projected on the three video tubes IR, IG, and IB are combined into a color image by two dichroic mirrors 3R and 3B, and this color image is transferred to the lens 4.
The image is enlarged and projected onto the screen 5.

The television image projection device having the configuration shown in FIG. Compared to a television image projection device that uses lenses 4R, 4G, and aBi to project enlarged images onto the screen 6 and superimposes three-color images on the screen 6, the disadvantage is that it is more susceptible to the effects of external magnetic fields such as earth's magnetism. have. Therefore, if you once adjust the convergence of the television image projection device and then move or change the direction of the television image projection device, the static convergence may be significantly distorted due to the influence of the earth's magnetic field. be. In the case of the television image projection device shown in Fig. 2, the three picture tubes 1R11G and 1B are arranged in a nearly parallel arrangement, so even if they are affected by an external magnetic field, the three picture tubes cannot be projected. Since the images projected on the tubes 1R, 11G, and 1B are translated in approximately the same direction and by approximately the same distance, the static convergence deviation is very small and can be ignored in practical terms. However, in the case of a television image projection device as shown in FIG.
, 1B are not arranged in parallel, so when the external magnetic field changes, the images projected on the three video tubes 1R91G and 1B are as follows.
Since they each move in parallel in different directions, the static convergence is greatly distorted.

By the way, as a method of escaping from the influence of external magnetic fields, it is conceivable to surround the entire picture tube with a magnetic material with very high magnetic permeability for magnetic shielding, as seen in an oscilloscope. In the case of the television image projection device shown in Figure 1, if all three picture tubes are surrounded by a magnetic material with high magnetic permeability, the static convergence shift due to the influence of external magnetic fields can be made extremely small. However, such high permeability magnetic materials are expensive and difficult to use.

Object of the Invention The present invention provides a television image projection device that performs color synthesis using a dichroic mirror, in which static convergence error due to the influence of an external magnetic field as described above is avoided.
It is an object of the present invention to provide an automatic static convergence adjustment device that can automatically adjust the convergence adjustment of a television image projection device and further simplify the convergence adjustment itself of a television image projection device.

Structure of the Invention The present invention uses the required pattern signal generator to generate red,
The point images for adjustment of each color of green and blue are imaged on a light receiving device installed at a predetermined location outside the effective surface of the full projection screen, and the point images for adjustment of each of the colors of red, green, and blue are received. A means for detecting a position (hereinafter referred to as a spot position) on the device drives a static convergence circuit for each color layer of red, green, and blue until the spot positions of each color of red, green, and blue match. It is composed of

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings. Third
The figure is a system configuration diagram when the present invention is applied to a television image projection device using a transmissive screen as an embodiment of the present invention. In the figure, in the television image projection device itself, the switch 6 is normally turned to the A side, and when the video electrical signal (V) is input to the video tube drive device 7, the switch 6 turns red.
A color image of green and blue is projected onto a transmission screen 9 via a lens 4 and a total reflection mirror 8. The pattern signal generator 10 is shown in FIG.

As an example, it is assumed that a test pattern having a dot pattern in the center of the screen that changes in red, green, and blue in a time-divisional manner is generated. The present invention attempts to adjust the static convergence by using the dot pattern to automatically control the positions of the color images of the dot pattern on the transmissive screen 9 so that they match. First, the switch 6 is turned to the B side, and the pattern signal generator 1o emits red light.

Green and blue pattern signals are generated in a time-sharing manner. Consider now a case where a red pattern signal is being generated from the pattern signal generating device 1o. The red pattern signal drives the red picture tube IRi by the picture tube drive device 7 to output a red pattern signal light, and the red pattern signal light is transmitted to the lens 4. A light receiving device 12 is installed at a predetermined position outside the effective surface of the transmission screen 9 via a sub-mirror 11.
incident on . The sub-mirror 11 is located in front of the total reflection mirror 8 only during the convergence adjustment period, and has the function of making the dot pattern signal light incident on the light receiving device 12. The light receiving device 12 performs optical-to-electrical conversion on the incident red pattern signal light and outputs the same.
position at the surface (i.e. static convergence shift,
(hereinafter referred to as the position of the red pattern). The horizontal static convergence adjustment device 14H1 and the vertical static convergence adjustment device 14V generate correction signals (respectively) of appropriate values to adjust the horizontal and vertical directions of the static convergence for the red beam from the position of the red pattern. EH, Ev) is generated. Next, the switches 15H and 15V switch on the red and green signals generated by the pattern signal generator 1o.

It opens and closes for a certain period of time in synchronization with the switching timing of the blue dot pattern, and in this case, the correction signal of the red beam is sent to the next stage memory (storage device) 1eHR, 1eVRI.
/Cden Elo Said memo! J-16I (n.

16HG, 16HB, 1eVR, 1eVG, 1eV
B stores and holds the correction signal r[(EH,Ey)' until the static convergence adjustment is performed again, and also supplies the correction signal (EH,Ey) to the convergence circuit existing in the picture tube drive device 7. The correct static convergence state is maintained by continuing to apply e. The static convergence is adjusted by the same process for green and blue beams.

Next, the functions of the light receiving device and the arithmetic device will be explained in more detail using FIG. As illustrated in FIG. 6, the light receiving 1° device 12 includes at least four photoelectric conversion elements 12a, 12b, 12c, such as photodiodes, each having sensitivity in the visible light region.

12d'j5 are installed close to each other, and each of the photoelectric conversion elements 12a to 12d performs optical-to-electrical conversion on the optical signal received on its surface and outputs it. Let those outputs be El,
E2. E3. Set it to E4.

FIGS. 6(a), 6(b), and 6(c) show several positions of signal light having a round cross section on the photoelectric conversion element of the light receiving device. When the center of the spot of the signal light (hereinafter referred to as the spot center) coincides with the center of the light-receiving surface (hereinafter referred to as the center of the light-receiving surface) composed of the four photoelectric conversion elements However, at this time, the output of the light receiving element is E1=E2-E3=E4 ・Old...(
1).

In the same figure (b), the spot center is shifted to the right side in the horizontal direction from the center of the light receiving surface, but at this time, between the light receiving element outputs, (E1+E2)>(E3+E4)...
・(2) There is a relationship.

Moreover, the same figure (C) shows a case where the spot center is shifted vertically downward from the center of the light receiving surface, and at this time, between the light receiving element outputs, (E2+E3)>(E1+E4)...・
...(3) There is a relationship.

As can be understood from the above, the output of the light receiving element (E1+
By comparing the combined outputs of E2) and (E3+E4), the horizontal deviation amount of the signal light spot can be determined, and by comparing the combined outputs of (E2+E3) and (E1+E4), the vertical deviation of the signal light spot can be determined. The amount of deviation in direction can be detected. Therefore, the specific configuration of the arithmetic unit 13 is, as shown in FIG. .E3+E4.
E2+E3. E1+E4) four adders 17,
There is a comparator 18 that compares the outputs of the adder 17 and generates an output (EH', EV') according to the difference between the output values of both skin calculators. As explained in , the present invention automatically corrects the static convergence shift caused by the external magnetic field of a television image projection device that enlarges and projects the image fft' projected on a plurality of picture tubes onto a screen using a lens. In addition to the adjustment, it also simplifies the static convergence adjustment itself, and its effects are extremely significant.

[Brief explanation of the drawing]

1 and 2 are schematic configuration diagrams of a normal television image projection device, FIG. 3 is a system configuration diagram showing an embodiment of the present invention, and FIG. 4 is a static convergence adjustment test presented in the present invention. A diagram showing an example of the pattern, Figure 6 is the third
Specific circuit diagram of the main part of the figure, Figure 6 (a), (b),
(c) is an explanatory diagram of the operation of FIG. 6. IR, IG, 1B...Picture tube, 3R, 3B...
・3 Guicroic mirror, 4...lens, 6...
...Switch, 7...Picture tube drive device, 8...
... Total reflection mirror, 9... Transmissive screen,
10... Pattern signal generator, 11...
...Sub mirror, 12... Light receiving device, 13...
... Arithmetic unit, 14H, 14V ... Static convergence m arrangement fM, 15Hl 15V ... Switch, 16HR, 1eHG, 1 eHB, 16V
R. 16vG, 16vB...Memory, 17...
...Adder, 18...Comparator. Name of agent: Patent attorney Toshio Nakao and one other person Figure 4'-",-" Figure 6/2c 494-

Claims (1)

[Scope of Claims] 0) Used in a television image projection device that enlarges and projects images projected on a plurality of picture tubes onto a screen using lenses, and includes a pattern signal generating device, red color, and green color. , an optical axis converting means for changing the optical axis of the television signal light projected from each blue tube, and an optical axis converting means installed at a predetermined position outside the effective surface of the projection screen to receive the television signal light and generate an electrical signal. a light receiving device that converts into
a computing unit that calculates the position of the television signal light on the surface of the light receiving device from the output of the light receiving device; a static convergence adjustment device that generates a correction signal for moving the television signal light so that it is at a predetermined position on the surface of the light receiving device;
il2 for a certain period of time. An automatic static convergence adjustment device comprising: a storage device for storing memory; (2) The pattern signal generation device time-divisionally generates a convergence adjustment pattern for each color signal component of red, green, and blue in the television signal at a certain timing,
The output of the static convergence adjustment device is characterized in that red, green, and blue correction signals are time-divisionally switched in synchronization with the timing of the convergence adjustment pattern generated by the pattern signal generation device, and are stored in the storage device. An automatic static convergence adjustment device according to claim (1).