KR0181280B1 - Zoom fading circuit - Google Patents

Abstract

The present invention relates to a zoom fade circuit that allows a fade function of a camcorder to operate in conjunction with a zoom function. In the related art, a zoom function and a fade function are independently performed to perform a fade function in conjunction with a zoom function.

Therefore, after the OA gate OR1 detecting the pressing of the zoom switches 11 and 12 and the position detecting means for detecting the end position of the zoom are provided, the zoom end position is detected when the fade switch 35 is turned on. By performing a fade out function and pressing the zoom switch 11 or 12 again, the microcomputer 40 performs a fade in function so that the fade function is performed in conjunction with the zoom function to provide a natural and smooth fade screen. It can be applied to camcorder and widely used.

Description

Zoom fade circuit

1 is a conventional zoom circuit diagram.

2 is a conventional fade circuit diagram.

3 is a circuit diagram of the present invention.

4 is a flow chart of the present invention microcomputer.

* Explanation of symbols for main parts of the drawings

10: motor control IC 11,12: zoom switch

20: zoom motor 30: fade circuit

35: fade switch 40: micom

OR1, OR2: ora gate CP1, CP2: comparator

I1: Inverter Q1: Transistor

The present invention relates to a zoom fade circuit for operating a fade function in conjunction with a zoom function in a camcorder having a zoom function and a fade function, and in particular, zoom in / out The fade in / out function is performed in the out state to perform a smooth fade function.

In existing camcorders, the zoom and fade functions are performed separately. Therefore, the zoom in / out button had to be pressed during the zoom operation, and the fade in / out button had to be pressed during the fade function.

Therefore, in the related art, it is easy to perform operations on individual functions, but it is difficult to simultaneously perform two functions in conjunction.

That is, in the conventional zoom circuit, as shown in FIG. 1, the motor control IC 10 detects the selection of the zoom switches 11 and 12 and the time when the selected zoom switches 11 and 12 are pressed by the motor control IC 10. 20) to control.

Here, the motor control IC 10 controls the rotation direction of the zoom motor 20 according to the pressing of the zoom switches 11 and 12 and controls the amount of rotation according to the pressing time of the zoom switches 11 and 12. .

In addition, the zoom motor 20 performs a zoom in / out operation by moving the zoom lens according to the output of the motor control IC 10.

Therefore, when the camcorder user wants to perform the zoom function, the user should select and press the zoom switches 11 and 12.

On the other hand, in the conventional fade circuit, as shown in FIG. 2, the luminance (Y) and the color (C) signals are gain-controlled by the voltage control amplifiers 31 and 32, and then the synchronization signal and the mixer 33 are controlled. The mixing is applied to the signal recorder 34, but the gains of the voltage control amplifiers 31 and 32 are controlled by the charge / discharge voltages of the fade switch 35 and the capacitor C1.

Here, the higher the gain voltage applied to the voltage control amplifiers 31 and 32, the lower the gain of the luminance Y and the color C signals, and the lower the gain voltage, the higher the gain.

Therefore, when the fade switch 35 is turned on, it becomes a fade out, and when the fade switch 35 is turned off, it fades in.

That is, when the fade switch 35 is turned on, the power supply Vcc is charged to the capacitor C1 and is applied to the voltage control amplifiers 31 and 32, so that the gain voltage of the voltage control amplifiers 31 and 32 is reduced to the capacitor C1. It gradually increases with the charging time constant of) to lower the gain of the luminance (Y) and color (C) signals so that they fade out.

However, when the fade switch 35 is turned off, the charge charged in the capacitor C1 gradually decreases, and thus the gain voltages of the voltage control amplifiers 31 and 32 are lowered, thereby reducing the luminance (Y) and the color (C) signals. Increase the gain so it fades in.

At this time, the fade in / out time is determined by the capacity of the capacitor C1, but the fade out time is set to be slower than the fade in time.

As described above, it is difficult to operate the zoom function and the fade function in a camcorder because the fade switch 35 must be operated when the fade function is performed and the zoom switches 11 and 12 must be operated when the zoom function is performed.

In view of the above problems, the present invention aims to perform a more natural fade function by operating a fade function of a camcorder in conjunction with a zoom function. In particular, the fade out function is operated while zooming out while zoomed in. This is to make the fade in function operate while zooming in in the zoom out state to make the fade scene more smooth and natural during fade in / out.

In order to achieve the above object, the present invention includes a signal detecting means for checking a zoom switch output to detect a zoom function selection, and a position detecting means for detecting an end position of the zoom motor, and a position detecting signal of the position detecting means. And a switching means for outputting a fade control signal when a zoom function selection signal of the signal detection means is applied when the fade selection signal is applied, and switching means for switching the fade control signal of the control means to apply to the fade circuit. It is.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is a circuit diagram of the present invention, wherein the camcorder has a motor control IC 10 for controlling the driving of the zoom motor 20 in response to the pressing of the zoom switches 11 and 12 and the pressing of the fade switch 35. A fade circuit 30 is configured to adjust the gain of the luminance and color signals.

The zoom selection signal according to the pressing of the zoom switches 11 and 12 is detected at the oragate OR1 and applied to the terminal ZOOM of the microcomputer 40.

In this case, when any of the zoom switches 11 and 12 is pressed, the high level is applied to the terminal ZOOM of the microcomputer 40.

The motor control voltage applied to the zoom motor by the motor control IC 10 is applied to the comparator CP1 and CP2 to be compared with the reference voltage REF, and the output of the comparator CP1 and CP2 is the oragate OR2. After the logical sum in the ()) is applied to the terminal (SLIP) of the microcomputer 40.

At this time, the motor control voltage output from the motor control IC 10 is 3V when the zoom motor 20 is operated, and the zoom position is ended, so the motor control voltage is 2.8V when the zoom motor 20 is not moving and the reference voltage REF is 2.9V. Set to.

Therefore, the comparator CP1 and CP2 output a high level at the end position of the zoom.

The fade switch 35 is connected to the terminal FADE of the microcomputer 40, and the transistor Q1 is connected to the terminal CTRL through the inverter I1, but the collector output of the transistor Q1 is connected to the fade circuit 30. Configured to be applied with a fade voltage.

At this time, the microcomputer 40 outputs the high level to the terminal CTRL when the high level is applied to the terminal FADE (SLIP), and to the terminal CTRL when the high level is applied to the terminal FADE (SLIP) (ZOOM). Output the low level.

The flow chart of such a microcomputer 40 is as shown in FIG.

That is, if the terminal FADE is high level, it checks whether the terminal SLIP is high level and outputs the high level to the terminal CTRL when the terminal FADE (SLIP) is all high level. In this state, the terminal Z00M If the level is high, the low level is output to the terminal CTRL.

This invention is demonstrated concretely.

First, the zoom motor 20 is selected by the motor control IC 10 by applying the motor control voltage to the zoom motor 20 by recognizing the selection state of the zoom switches 11 and 12. In driving with, the general motor driving voltage is applied to the zoom motor 20 at 3V when the power supply Vcc voltage is applied at 5V and at 2.8V when the zoom position is at the end.

The motor driving voltage is applied to the inverting terminal (-) of the comparator CP1 (CP2) and the reference voltage REF is applied to the non-inverting terminal + at 2.9V.

The comparator CP1 (CP2) then outputs a low level when the zoom motor 20 is operating (when the motor drive voltage is applied at 3V) and outputs a high level when the zoom position is terminated (when the motor drive voltage is 2.8V). The outputs of these comparators CP1 and CP2 are ORed at the OR gate OR2.

Therefore, when the zoom motor 20 operates, the output of the oragate OR2 is at a low level, and at the zoom end position where the zoom in / out operation is completed, any one of the outputs of the comparator CP1 (CP2) is at a high level. The output of OR2 also becomes a high level.

In other words, the moment the output of the oragate (OR2) becomes a high level, it turns out to be the zoom end position.

The output of the oragate OR2 is applied to the terminal SLIP of the microcomputer 40.

On the other hand, the ORA, which is connected to the zoom switches 11 and 12 and detects the pressed state (zoom state) of the zoom switches 11 and 12, has a high level when the zoom switches 11 and 12 are selected. The output of the OR gate OR1 is applied to the terminal ZOOM of the microcomputer 40.

In addition, when the fade switch 35 is turned on to connect the fade switch 35 to the terminal FADE of the microcomputer 40, a high level is applied to the terminal FADE of the microcomputer 40.

Here, the microcomputer 40 outputs the high level to the terminal CTRL when the high level is applied to the terminal FADE (SLIP), and outputs the low level when the high level is applied to the terminal FADE (SLIP) (ZOOM). Normally, the high level output from the terminal CTRL is maintained for 6-7 seconds (fade time).

The terminal CTRL output of the microcomputer 40 is inverted in the inverter I1, inverted in the transistor Q1, and then applied to the fade circuit 30.

A description with reference to the flowchart of FIG. 4 is as follows.

First, the fade switch 35 is turned on to shoot using a camcorder while a high level is applied to the terminal FADE of the microcomputer 40.

Even if the camcorder is operated with only the fade switch 35 turned on, the fade function is not performed and the fade function is not performed even when the zoom function using the zoom switches 11 and 12 is not used. .

However, if you want to operate the camcorder by turning on the fade switch 35 and then perform the fade function, move the zoom end position using the zoom switches 11 and 12 to output the OA gate OR2 as described above. The high level is applied to the terminal SLIP of the microcomputer 40.

Then, the microcomputer 40 outputs a high level to the terminal CTRL, inverts the inverter I1 and the transistor Q1, and applies the same to the fade circuit 30 so that the fade out operation is performed.

That is, when the fade switch 35 is turned on and moved to the zoom end position using the zoom switches 11 and 12, the microcomputer 40 detects this and executes the fade out function.

At this time, the high level output outputted from the terminal CTRL of the microcomputer 40 is normally maintained for 6-7 seconds, but is immediately outputted to the low level when the zoom switches 11 and 12 are selected.

That is, when the terminal FADE (SLIP) of the microcomputer 40 becomes high level and the high level is applied to the terminal ZOOM by selecting the zoom switches 11 and 12 while the fade out function is performed, the terminal CTRL To apply low level to zoom in operation.

Therefore, the present invention can perform a fade out function while zooming out at the end position where the zoom in operation is completed, and operate the fade in function while zooming in at the end position where the zoom out operation is completed, and fade in in conjunction with the zoom in / out operation. The / out function is performed to provide a smooth and natural fade scene.

Claims (4)

A camcorder for controlling the driving of a zoom motor in a motor control IC according to a zoom switch input and performing a fade function in a fade circuit, comprising: signal detecting means for checking a zoom switch input to detect a zoom function selection, and an end position of the zoom motor Control means for recognizing a position detecting means for detecting a signal, a position detecting signal of the position detecting means, a fade selection signal by the fade switch and a detecting signal of the signal detecting means, and outputting a fade control signal; A zoom fade circuit comprising a switching means for switching and applying to a fade circuit. 2. The zoom fade circuit according to claim 1, wherein the signal detecting means is constituted by an OR gate for ORing the input of the zoom switch and configured to apply an output of the OR gate to the microcomputer. The position detecting means comprises: two comparators for comparing the motor control voltage applied to the zoom motor by the motor control IC with a reference voltage, and an oar gate for logically combining the outputs of the two comparators and applying them to the microcomputer. Zoom fade circuit. The microcomputer according to claim 1, wherein the control means outputs a fade out control signal when the fade selection signal of the fade switch and the position detection signal of the position detection means are applied, and outputs a fade in control signal when the detection signal of the signal detection means is applied. Zoom fade circuit composed of.