KR950003168Y1 - Lens projection ration compensation circuit of projection apparatus - Google Patents

Abstract

No content.

Description

Lens Transmittance Compensation Circuit of Progressive Display

1 is a circuit diagram of the present invention.

Figure 2a-d is the operation waveform diagram of each part for explaining the present invention.

3 is a graph showing the transmittance of the lens in the horizontal and vertical direction in the present invention.

4 is a schematic configuration diagram of a conventional projection display device.

* Explanation of symbols for main parts of the drawings

1-3: Caliber Compensation Circuit 4-6: Image Output Circuit

7-9: CPT 10-12: Modulator

13 horizontal sawtooth wave generator 14 horizontal parabolic wave generator

15: vertical parabolic wave generation

The present invention relates to a lens light transmittance compensation circuit of a projection type display, and in particular to a display device requiring a high definition such as a high-definition TV receiver, a projection type display whose contour can be optimally adjusted over the entire screen. A lens transmittance compensation circuit of an apparatus is provided.

In the conventional projection display device, as shown in FIG. 4, the output terminals of the aperture compensation circuit sections 31-33 to which the R, G, and B color signals are input are respectively CPT through the image output circuit sections 34-36. It is connected to (Color picture Tube) (37-39) and its operation relation is as follows.

First, the R, G, and B color signals are amplified by the aperture compensation circuit unit 31-33 and the image output circuit unit 34-36 each consisting of a delay line and first and second differentiators. -39), the contour is displayed as a compensated signal, in which the center and periphery of the lens respectively installed in the CPT (37-39) of the projection display device are compensated for by the same compensation with the aperture-calibrable variable resistor (VR1). Since the transmittance for is different, even if the amount of correction is appropriate in the center, there is a lack of feeling at the peripheral part. On the contrary, if the peripheral part is optimally adjusted, the entire screen is displayed unnaturally because the contour is too much emphasized due to excessive correction at the center part. There was this.

The present invention was devised to solve such a conventional problem, and by adding a plurality of modulators, horizontal sawtooth wave generators, and horizontal and vertical parabolic wave generators to a conventional projection display device, the transmittance difference between the center and the periphery of the lens is different. It is an object of the present invention to provide a lens transmittance compensation circuit of a projection display device that can reproduce a shape having an optimal contour over the entire screen while compensating for the above, and will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the structure of the present invention is a projection type display device in which the aperture compensation circuit section 1-3, the image output circuit section 4-6, and the CPT 7-9 are interconnected. Between the aperture compensation circuit section 1-3 and the image output circuit section 4-6, a modulator 10-12 is formed by connecting transistors Q7-Q12, resistors R24-R34, and capacitors C12, C13, respectively. In addition, the output terminal of the horizontal sawtooth wave generator 13, in which the transistors Q1, the resistors R1-R5, the capacitors C1-C3, and the diode D1 are configured to be interconnected so that a horizontal pulse is input through the input terminal, may be a transistor ( Q2-Q4), resistors R6-R15, variable resistors VR1, and capacitors C4-C7 are interconnected to the inputs of the horizontal parabola and generator 14, transistors Q5, Q6, Resistor (R16-R23), variable resistor (VR2), and capacitor (C8-C11) are interconnected so that the vertical sawtooth wave is input to the input terminal and horizontal with the output terminal of the vertical parabolic wave generator 15 The output terminal of the parabolic wave generator 14 is configured to be connected to the control terminal CO of the modulator 10-12 in common, where reference numeral VR3 denotes a variable resistor for controlling the aperture compensation amount, Fig. 1 shows the transmittance of the center and periphery of the lens attached to the CPT of the projection display device in the horizontal and vertical directions, where a is a graph showing the transmittance of the lens, and b is the same contour throughout the screen. Is a graph of inverse characteristics to compensate for a.

Referring to the effect of the present invention configured as described with reference to Figures 2a-d and 3 as follows.

First, the aperture compensating circuit unit 1-3 compensates the apertures of the R, G, and B color signals by the resistance value of the variable resistor VR3, and its output is as shown in FIG.

On the other hand, the horizontal pulse of the square wave output from the deflection circuit not shown is converted into the horizontal parabolic waveform like b degree of FIG. 2 via the horizontal sawtooth wave generator 13.

In addition, the vertical sawtooth wave is also converted into a vertical parabolic waveform such as c in FIG. 2 through the vertical parabola and the generator 15. The two waveforms, that is, the horizontal and vertical parabolic waveforms, are combined with each other so that the control terminal CO of the modulator 10-12 ) Is entered.

Therefore, the modulator 10-12 outputs a signal such as a degree of FIG. 2 obtained by modulating a signal such as a degree of FIG. 2 output from each aperture compensating circuit unit 1-3 into horizontal and vertical parabolic waves. The image appearing on the CRT 7-9 through (4-6) is displayed with an even contour as a whole.

In addition, the compensation amount is first set by the aperture compensating amount control variable resistor VR3 so that the contour compensation is optimal at the center, and then the contour compensation is set for the periphery. By adjusting the amplitude of the parabolic wave (i.e., b degree in FIG. 2) of the fine horizontal period H, it is possible to change the correction amount in the center and periphery of the lens, and for the peripheral part in the vertical direction, the parabolic of the vertical period V which is a modulation wave. By adjusting the amplitude of the wave (i.e., c degree in FIG. 2), it is possible to change the correction amount of the central portion and the peripheral portion.

Referring to this relationship in more detail with reference to Figure 1, first, the horizontal pulse input through the resistor (R1) is an integrated circuit consisting of capacitors (C1, C3), resistors (R2-R5) and transistors (Q1). The transistor Q4 is first integrated through the transistor Q2 and then amplified through the transistor Q2, and then integrated through the transistor Q3, the resistors R8-R12, and the capacitor C6. It is then amplified and applied to the horizontal parabolic and amplitude adjustable variable resistor VR1.

In addition, the vertical sawtooth wave input through the resistor (R16) is amplified through the transistor (Q5) and then integrated through an integrated circuit consisting of resistors (R21, R22), transistor (Q6) and capacitor (C10) and then the vertical parabolic and It is applied to the amplitude control variable resistor VR2.

On the other hand, the horizontal and vertical parabolic waveforms applied to the variable resistors VR1 and VR2, respectively, are combined with each other through the capacitors C7 and C11 and the resistors R15 and R23, and then the transistors Q8 and Q9 of the modulator 10-12. Is applied to the base.

Therefore, the aperture compensation signal input through the resistor R23 in the modulator 10-12 is falsified by the modulating wave applied to the bases of the transistors Q8 and Q9, and the collectors of the transistors Q8 and Q10 are shown in FIG. The modulation waveform as shown is output, where resistors R25, R26 and R34 are bias resistors of transistors Q7 and Q10, and resistors R25, R27 and R34 are bias resistors of transistors Q8 and Q9. R32 and R33 are bias resistors of the transistor Q12, and the transistors Q11 and Q12 are constant current source circuits.

As described above, according to the circuit of the present invention, the contour of the screen is effectively compensated by the difference between the permeability of the lens attached to the CPT of the projection display device due to the difference in the permeability of the lens. It is adjusted so that a more beautiful screen can be reproduced.

Claims (1)

A horizontal sawtooth wave generator 13 for converting an input horizontal pulse into a sawtooth wave, a horizontal parabolic wave generator 14 for converting a horizontal sawtooth wave output from the horizontal sawtooth wave generator 13 into a parabolic wave, and an input vertical sawtooth wave as a parabolic wave The vertical parabolic wave generator 15 and the R, G, B color signals compensated by the aperture compensation circuit unit 1-3 are respectively converted according to the output signals of the horizontal and vertical parabolic wave generators 14 and 15, respectively. A projection type characterized in that it comprises a modulator (10-12) for amplifying and an image output circuit section (4-6) for processing the output signals of the modulator (10-12) and outputting them respectively to the CPT (7-9). Lens transmittance compensation device of a display device.