JPH0142554B2 - - Google Patents

Description

[Detailed Description of the Invention] In a multi-tube color television camera, if the positional relationship between the subject image projected on the photoelectric conversion surface and the scanning position of the electron beam differs depending on the image pickup tube, color shift may occur on the reproduced screen. It will happen. Therefore, in a multi-tube camera, it is necessary to accurately match the positional relationship between the subject image and the scanning position of the electron beam.

The present invention is intended to enable such alignment and, in particular, to simplify the configuration therefor.

An example of this will be explained below. In this example, the camera is a three-tube type, and the positional relationship between the subject image in the green image pickup tube and the scanning position of the electron beam is used as a reference, and the positional relationship between the subject image and the electron beam in the other image pickup tubes is used as a reference. This is a case where the positional relationship with the scanning position of the beam is adjusted in the vertical direction.

In Figure 1, 1G, 1R, 1B are for green;
The image pickup tubes for red and blue are shown, 2G, 2R, 2
B is, for example, a deflection coil. And image pickup tube 1
Green, red, and blue color signals G from G, 1R, and 1B,
R and B are taken out, but in this case, a DC bias current is supplied to the deflection coil 2G and the image pickup tube 1G
The vertical scanning position of the electron beam is shifted in the vertical direction by one scanning line, and the green signal G is taken out at a time point (phase) that is one horizontal period ahead of the original time point.

Then, this signal G is supplied to the first delay circuit 3, and as shown in FIGS. 2A and 2B, it is made into _a signal _G1 delayed by one horizontal period.
2. Furthermore, since the signal G is located at a time point one horizontal period ahead of the original time point, this signal _G1 is located at the original time point, and this signal _G1 is the positioning point. becomes the standard.

Furthermore, if the positional relationship between the subject image and the scanning position of the electron beam in the image pickup tube 1R matches the positional relationship in the image pickup tube 1G, a signal R having the same phase as the signal _G1 is extracted from the image pickup tube 1R. , if the positional relationship between the subject image in the image pickup tube 1R and the scanning position of the electron beam is shifted, then the image pickup tube 1R
When the scanning position of the electron beam is shifted downward when viewed from the subject image, a signal R with an advanced phase is obtained as shown by the solid line in Figure 2G, and when it is shifted upward, it is indicated by the broken line. As shown, a signal R with a delayed phase is obtained. Further, the phase amount τ of this signal R corresponds to the magnitude of the shift in the positional relationship between the subject image in the image pickup tube 1R and the scanning position of the electron beam.

This signal R is then supplied to the subtraction circuit 12 through the switch circuit 11, which has been switched to the state shown in the figure by the control circuit 20, and the signal _G1 and R are subtracted, resulting in the result shown in FIG. 2H. A difference signal (G ₁ -R) is taken out, and this signal (G ₁ -R) is supplied to sampling and holding circuits 13 and 14. In this case, the polarity of the signal (G ₁ −R) is
The direction of the positional deviation in the red image pickup tube 1R is shown, and the pulse width τ indicates the magnitude of the deviation.

Further, _the signal G ₁ is supplied to the second delay circuit 4 and is further delayed by one horizontal period as a signal G ₂ as shown in FIG. Then, a difference signal (G-G ₂ ) is extracted as shown in FIG. 2D. Then, this signal (G-G ₂ ) is supplied to the voltage comparison circuits 6 and 7, and from the comparison circuit ₆ , as shown in _FIG . Pulse P ₆ which becomes “1” is taken out and comparator circuit 7
As shown in FIG. 2F, a pulse P7 which becomes "1" during two horizontal periods _T7 centered at the falling edge of the signal _G1 is taken out. Therefore, the signal (G
-G ₂ ) or the pulses P ₆ and P ₇ will indicate a change in the color saturation of the green subject image, that is, they will indicate the edges of the green subject image.

A signal (G ₁ -R) in which the pulses P ₆ and P ₇ are supplied as control signals to the sampling and hold circuits 13 and 14 is sampled and held.

In this case, as shown in FIG. 1, the sampling and holding circuits ₁₃ and ₁₄ have capacitors for holding, so that the signals (G ₁ - R) is integrated, and this integrated value is held at "0" time. Therefore, from the sampling and holding circuit 13, the polarity of the signal (G ₁ -R), that is, the direction of the positional deviation in the red image pickup tube 1R, is output as shown by a solid line or a broken line in FIG. 2I. A DC voltage V ₃ whose polarity is reversed is taken out from the sampling and hold circuit 14, and a DC voltage V 4 whose polarity is similarly reversed and whose polarity is opposite to that of the voltage V ₃ is output from the sampling and hold circuit ₁₄ , as shown in FIG. 2J. taken out.

Then, these voltages V ₃ and V ₄ are applied to the voltage comparator circuit 15.
When V ₃ < V ₄ (solid line), “0”
Then, when V ₃ > V ₄ (dotted line), a signal S ₅ that becomes “1” is extracted, and this signal S ₅ is supplied to the up-down counter 1 as a control signal for the count mode, and is also supplied to the counter 16. is control circuit 2
From 0 onwards, a vertical synchronization pulse Pv is supplied as a count input. Then, the count value of the counter 16 is passed through the memory 17R to the D-A converter 18R.
This voltage Vr is converted into a current Ir in an amplifier 19R, and the current Ir is supplied to a deflection coil 2R.
supplied to

Therefore, if the scanning position of the electron beam is shifted downward when viewed from the subject image in the image pickup tube 1R, the phase of the signal R advances as shown by the solid line in FIG. 2G, so S ₅ = "0", the counter 16 counts up the pulse Pv. Therefore, the voltage Vr rises and the current Ir increases. Therefore, the scanning position of the electron beam in the image pickup tube 1R is upward when viewed from the subject image. It changes to.

On the other hand, if the scanning position of the electron beam is shifted upward when viewed from the subject image in the image pickup tube 1R, the phase of the signal R is delayed as shown by the broken line in _FIG . ”, the counter 16 counts down the pulse Pv, and as a result, the voltage Vr decreases and the current Ir decreases, so the scanning position of the electron beam in the image pickup tube 1R changes downward when viewed from the subject image. It's changing.

Therefore, for each pulse Pv the counter 16
The count value of is incremented (when S ₅ = “0”) or decremented (when _{S 5} = “1”)
At the same time, this count value is stored in the memory 17R.
Since the current Ir corresponding to the count value is supplied to the deflection coil 2R, the scanning position of the electron beam in the image pickup tube 1R changes in a direction that matches the object image. That is, even if the phase relationship between the subject image in the image pickup tube 1R and the scanning position of the electron beam is shifted, this shift is corrected to 0 with each pulse Pv.

Then, when the shift in this phase relationship becomes small to the resolution of this circuit, the signal S ₅ becomes 1 of the pulse Pv.
"0" and "1" are repeated every time, but this is detected by the control circuit 20, and the enable signal from the control circuit 20 becomes "0".
This causes the counter 16 to stop counting, and the count value of the counter 16 at this time is written to the memory 17R and held fixed.
Thereafter, a current Ir is applied to the deflection coil 2R based on the data in the memory 17R.

Therefore, the positional relationship between the subject image and the scanning position of the electron beam in the image pickup tube 1R matches the positional relationship of the reference image pickup tube 1G.

In this way, when the positioning of the image pickup tube 1 is completed, the switch circuit 11 is switched to the opposite state as shown in the figure by the control circuit 20, and from then on, the image pickup tube 1
A similar operation is performed for B. In addition, circuit 1
7B to 19B and signals Vb and Ib are connected to circuits 17R to 19B.
19R and signals Vr and Ir.

Thus, according to the present invention, in the multi-tube color television camera, it is possible to match the positional relationship between the subject image in the image pickup tubes 1G to 1B and the scanning position of the electron beam. Moreover, in this case,
In particular, according to the present invention, there is no need for multiplier circuits, NAM circuits, etc. that were required in conventional circuits of this type, so the configuration can be simplified and costs can be reduced.

In addition, although the above is a case of alignment in the vertical direction, in the case of alignment in the horizontal direction, the delay time of the delay circuits 3 and 4 may be set to 1/2 pixel period; By switching the circuits 3 and 4 and making the memories 7R, 17B and subsequent channels equivalent to 4 channels, it is possible to align the two. Also,
The circuits 6 and 13 may be omitted, and the present invention can also be applied to the case where a plurality of color signals and luminance signals are obtained from one image pickup tube using a color separation filter.

Further, the counting of the counter 16 may be stopped when a certain number of pulses Pv have been counted (at this time, the signal _S5 has already repeated "0" and "1"), or , one D-A converter 18R, 18B is used, voltages Vr and Vb are held by capacitors, and one
D of memories 17R and 17B for each field period
- The capacitor voltages Vr and Vb may be refreshed using the A conversion output.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an example of the present invention, and FIG. 2 is a diagram for explaining the same. 3 and 4 are delay circuits, 16 is a counter, 17R,
17B is a memory, and 18R and 18B are DA converters.

Claims (1)

[Claims] 1. A circuit for extracting a signal indicating the edge of a subject image from an output signal of a first image pickup tube, a circuit for extracting a difference signal between the output signal of the first image pickup tube and the output signal of the second image pickup tube, and a circuit for extracting a difference signal between the output signal of the first image pickup tube and the output signal of the second image pickup tube. a sampling and holding circuit that samples and integrates the signal during the period of the edge signal and holds the signal thereafter;
A signal indicating the phase difference between the output signal of the image pickup tube and the output signal of the second image pickup tube is obtained, and this signal is supplied to the deflection means of the second image pickup tube to obtain the signal indicating the phase difference between the output signal of the image pickup tube and the output signal of the second image pickup tube. A multi-tube color imaging device configured to perform registration adjustment of a second subject image.