JPS61134795A - Horizontal deflection circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to horizontal deflection circuits for CRT displays and the like.

[Conventional technology]

The output of a personal computer is generally a dedicated CR.
It is designed to be displayed on a T display, monitor receiver, or television receiver (these display devices are
(collectively referred to as display).

In this case, as shown in FIG. 3, S
P is made small to prevent the periphery from being chipped.

However, depending on the combination of CRT display and personal computer, the front SP of the display range may
The horizontal position of the camera may shift.

Therefore, CRT displays that can adjust the horizontal position are being developed.

No. 4111I shows the horizontal deflection circuit of such a CRT display, i.e. the output of the horizontal output circuit (5) is supplied to the horizontal output H path (6) to generate horizontal deflection pulses as shown in FIG. 5A. A pulse P6 is formed, and this pulse P6 is supplied to the horizontal deflection coil DY to perform horizontal deflection, and is also supplied to the f-phase comparison circuit (4).

Further, a horizontal synchronization pulse ph is taken out from the synchronization separation circuit +11 as shown in FIG.

(3) is sequentially supplied to the multivibrator (2), as shown in FIG. ), as shown in the figure, a pulse P3 that rises at the trailing edge of the pulse P2 and has a predetermined pulse width is taken out. Then, this pulse P3 is supplied to a comparator circuit (4) to compare the phases of pulses P3 and P6, and the comparison output is supplied as a control signal to the oscillation circuit 173 (51) to pulse P6.
is synchronized to pulse P3.

In this case, during steady state, AFC is performed so that the center of pulse P@ and the center of pulse P3 coincide, as shown in A and D in the same figure, so as shown in A and H in the same figure, , the horizontal synchronizing pulse ph is applied to the horizontal deflection pulse Pε.
and the phase of the video signal sy will advance, so that
As shown in Figure E, Table 7rX range nrsp is screen SC1? It will be shifted to the left with respect to IJ. At this time, by changing the pulse width T of the pulse P2 in the multivibrator (2), the phase of the pulse ph with respect to the pulse P6 changes, so that the horizontal position of the display range I'1ISP can be adjusted.

[Problem that the invention seeks to solve]

However, as is clear from the above explanation, this deflection circuit can only advance the phase of the pulse ph with respect to the pulse P6, so even if T=0, the horizontal position of the sp in front of the display range is shifted to the right. It is not possible to shift the pulse P6 in the right direction. In order to shift it in the right direction, a similar monostable multi-channel signal is connected to the signal line of the pulse P6 between the output circuit (6) and the comparator circuit (4). A vibrator must be provided.

However, providing such a number of monostable multivibrators increases the cost, and in such a configuration, it is necessary to adjust the horizontal position of the display range 11TsP to the left and shift it to the right. Adjustment is also troublesome because the adjustments made are separate and affect each other.

This invention attempts to solve these problems.

[Means for solving problems]

Now, if we think about the operation of a transistor, there is an accumulation effect in the operation of a transistor, and even if the base voltage is set to the cutoff value, its collector current will not be cut off at the same time, but will be cut off after a delay of accumulation time Ts. It turns off.

This invention focuses on these points, and uses only one set of phase shift angle monostable multivibrators [7) and (8). It has been made possible.

[Effect]

The accumulation time Ts of the horizontal output transistor Q is equal to the horizontal pulse P.
The relative position of the horizontal deflection pulse P6 and the horizontal synchronizing pulse ph can be freely changed using only one set of monostable multivibrators (71, (81).

Furthermore, the horizontal position of the display range DISP can be shifted leftward and rightward with only one adjustment point.

〔Example〕

In FIG. 1, Q indicates a transistor for horizontal output, and the horizontal oscillation pulse P5 is supplied from the horizontal oscillation circuit (5) to the base of this transistor Q, and the horizontal deflection coil DY, ! is supplied to the collector of the transistor Q. : Resonant capacitor C1 and damper diode D are connected to form a horizontal output circuit (6
) is configured. Note that C2 is a capacitor for character 8 correction. Further, as shown in FIG. 2A, the drive pulse P6 is a signal having a horizontal period and a predetermined pulse width, and these pulses P5 and the output circuit (6) are of a general type.

When the pulse P5 is supplied to the base of the transistor Q, a sawtooth current Tc flows to the collector of the transistor Q in the latter half of the horizontal scanning period as shown in FIG. has an accumulation effect, so the current 1c decreases to V after the pulse P5 falls.
W becomes 0 (cutoff) after the elapse of the product time Ts. At this time, the horizontal deflection pulse is applied to the deflection coil DY at the cutoff point of the current Tc, as shown in diagram C. P6 is being paid.

Furthermore, the pulse P5 is sequentially supplied to the monostable multivibrator (71, (81) for variable phase shifting, and from the multivibrator (7), as shown in the figure, the pulse P5 rises at the trailing edge of the pulse P5, and the predetermined pulse A pulse P7 having a width T is emitted, and a pulse P8 rising from the trailing edge of the pulse P7 and having a predetermined pulse width is taken out from the multivibrator (8) as shown in FIG. , this pulse P@ is sent to the phase comparator circuit (4
), and the horizontal synchronization pulse ph from the synchronization separation circuit +11 is also supplied to the comparator circuit (4) without phase shifting, the pulse ph and P8 are phase-compared, and the comparison output is sent to the oscillation circuit ( 5) as a control signal so that the pulse P5 is synchronized with the pulse ph.

In this case, during steady state, AFC is performed so that the center of pulse P8 and the center of pulse ph coincide, as shown in E and F of the figure, so when the pulse width T of pulse P7 is small, , as shown on the left side of C and F in the same figure, the phase of the horizontal synchronizing pulse ph and the video signal Sν advances with respect to the horizontal deflection pulse P6, and therefore the display range as shown on the left side of G in the figure Mouth SP is screen 5C
It will be shifted to the left relative to the RN.

Furthermore, when the two pulses @T are large, the phases of the horizontal synchronizing pulse Ph and the video signal Sy are delayed with respect to the horizontal deflection pulse P6, as shown on the right side of C and F in the same figure. As shown on the right side of FIG. 1G, the display range opening SP is shifted to the right with respect to the screen 5CRN.

Thus, according to the present invention, the horizontal position of the display range +) TSP can be shifted leftward and rightward.

Moreover, in that case, especially according to the present invention, since the phase of the horizontal deflection pulse P6 is delayed using the accumulation time Ts of the transistor Q, only one set of low-stable multivibrators 171 and 181 for phase shifting is sufficient. , therefore, low cost.

Further, the adjustment is easy because the horizontal position of the display range opening ISP can be shifted to the left and right by simply changing the pulse width T of the pulse P7, that is, by just changing one adjustment point. According to experiments, the horizontal position of the display range [ll5P could be adjusted over a range of ±6 μsec, that is, over 195 (−±6 μsec/1 horizontal period).

If this CRT display is to be used for displaying television broadcasts, pulse P5 may be supplied to the comparator circuit (4) instead of pulse P8.

(Effects of the Invention) According to this invention, the horizontal position of the display range osp can be shifted to the left and right.Moreover, in this case, especially according to this invention, the storage time Ts of the transistor Q can be used. Since the horizontal deflection pulse P6 is connected in phase, only one set of monostable multivibrators (71, (81) for phase shifting is required, and therefore, the cost is low.

Further, the adjustment is easy because the horizontal position of the display range ntsp can be shifted to the left and right by simply changing the pulse width T of the pulse P7, that is, by just one adjustment point. According to experiments, the horizontal position of the display range DISP could be adjusted over a range of ±6 μsec, that is, over 195 (−±6 μsec/1 horizontal period).

[Brief explanation of drawings]

FIG. 11 is a system diagram of an example of the present invention, and FIGS. 2 to 5 are diagrams for explaining the same. +1) is a synchronous separation circuit, (4) is a phase comparison circuit, (5)
is a horizontal oscillation circuit, (6) is a horizontal output circuit, +71. +
81 is a monostable multivibrator.゛

Claims (1)

[Claims] The horizontal oscillation pulse of the horizontal oscillation circuit is supplied to the base of the horizontal output transistor of the horizontal output circuit, and is also sequentially supplied to the first and second monostable multivibrators for phase shifting, The output pulse of the multivibrator is supplied to the phase comparison circuit, and the horizontal synchronization pulse from the synchronization separation circuit is supplied to the phase comparison circuit,
The comparison output of this phase comparison circuit is supplied to the horizontal oscillation circuit as its control signal, and by changing the pulse width of the output pulse of the first monostable multivibrator, the comparison output is supplied from the horizontal output transistor to the horizontal deflection coil. A horizontal deflection circuit that adjusts the horizontal position of a display on a screen by changing the phase of the horizontal deflection pulse and the horizontal synchronizing pulse.