KR930011294B1 - Zoom motor control method of vtr camera - Google Patents

Abstract

The motor control method compensates the accumulative tolerance of the zoom lenses for getting the fine images. The accumulative tolerance caused by the deviation of the lense axis between the tele-mode and the wide-mode can be compensated by having the drive motor of the zoome lenses reversed for a while after finishing the tele-mode operation.

Description

Zoom motor control method of VTR camera with zoom function

1 is a cross-sectional view illustrating roller displacement of a barrel in relation to VTR camera zooming.

2 and 3 are flow charts in accordance with the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera for a VTR equipped with a zoom function, and more particularly, to a method for adjusting a lens array of a camera for a VTR equipped with a zoom function to obtain a desirable resolution by adjusting an arrangement state of a lens group during a zoom operation.

Along with the increase of portable portable VTRs, the demand for color video cameras for homes continues to increase. In accordance with this trend, the demand for use of the performance and functions of video cameras is also gradually increasing. In addition, small size, light weight, low power consumption, high performance and multifunctionality are pursued. At the same time, there is a need for an automatic function for improving the operability of the video camera, so that the automatic color adjustment function and the auto focus function are adopted in most cases. Still cameras require only one AF operation when the shutter is released, while video cameras require continuous AF operation and are relatively focal in video cameras with a wide to tele zoom function. The ability to focus with a few steps higher precision than a still camera using a fixed focal length lens is required.

In response to this demand, a cylindrical barrel mounted to a videocone to realize zooming, that is, tele and wide function, as shown in FIG. 1 showing a cross-sectional view of a combination of relevant components for zooming of a VTR camera equipped with a zoom function. 1) and the front lens block 4 which is moved up and down by the front cam roller 3 which is movable along the guide hole 2 provided in an inclined part of the barrel cam wall, and similar configuration. The rear group lens block which is movable up and down by the rear group cam roller is provided, and the plurality of gear groups 5 and the motor M for operating the gear group so that the barrel 1 can be rotated in the wide or tele direction. It is integrally configured to realize the zoom function of the VTR camera.

In the above case, as an example, the assembly for the electrically operable zooming is shown. When the motor M rotated by the user's selection of a tele or wide switch is rotated, it is connected to the motor shaft to obtain an appropriate rotational speed of the barrel. It rotates in mesh with gear group 5 for it.

Then, in the case of wide selection, as shown in the drawing, the lens block 4 shown by the dotted line inside the barrel 1 is moved downward, and in the case of the tele selection, the lens block 4 is moved upward to enlarge or reduce the distant subject, such as a videoconductor or a photographing tube. It is input to the image sensor.

In this case, designed for the zooming function, there is an inherent mechanical error between the gear group and the cam roller for conveying the lens group, which reduces the resolution of the image passing through the rearranged lens group with this error. It acts as a factor.

The deviation (Δh) between the centers of the rollers as the guide holes 2 and the rollers 3 connected to the guide holes 2 and the rollers 3 connected thereto in the enlarged view of FIG. It is shown in the figure.

That is, the position of the surface 2a of the guide hole and the roller 3 in the wide direction rotation, and the position of the surface of the guide hole 2 and the contact of the roller 3 in the tele direction rotation. Since the deviation (Δh) between the center of the roller is generated from this is caused by the gap between the lens of the front group and the rear group to generate a position difference on the film surface is a factor of the defect (PUNT).

In addition, the cumulative tolerance of the gear group depending on the mechanical arrangement is also a factor in the reduction of the removed resolution. Due to the tolerance, when moving from wide to tele side and from tele to wide side, the direction of force is different, resulting in a difference in distance between lens groups, which reduces resolution.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and in order to solve the problem, a control method of a program for a zoom motor that minimizes the change in resolution by controlling the zoom motor to compensate the cumulative tolerance is always operated in one direction. For the purpose of providing it.

That is, in the case of operating in the tele direction, reverse rotation is applied in the wide direction for the compensation of the accumulated tolerance at the stop position (shooting point), so that the arrangement between the front and rear lenses is constant at the stop position, thereby preventing deterioration of pedometer force.

The present invention will be described in detail with reference to the flowcharts according to the present invention of FIGS. 2 and 3 which are attached to a zoom motor control method of a VTR camera equipped with a zoom function according to the present invention.

First of all, the initial power and other operations are performed to use the VTR camera, and then the user inserts a tele or wide switch to zoom in to adjust the distance to the subject.

To this end, as shown in step 2-1 of FIG. 2, it is checked whether or not the teleswitch is turned on. If the teleswitch is turned on, the operation is performed as described below. If the teleswitch is not turned on, the process proceeds to step 2-2. Check whether the switch is on. In case of 'N', since no switch is input, it returns. In case of 'Y', since it is wide, the zoom motor (M) is rotated in reverse as in step 2-3 to enlarge the field of view. .

However, in consideration of the occurrence of the accumulated tolerance, the present invention compensates for this by the overtimer, which is a counter timer inside the CPU, and a timer value must be specified under the designed state of the VTR camera. However, in the case of wide, compensation is not made as follows. In other words, if the overtimer is turned on in step 5 together with the overtimer operation in step 4, if the overtimer is turned on in step 2-6, the motor is stopped immediately and the wide switch is turned on. If not, stop the motor as in Step 2-7.

This series of steps is to stop the zoom function (stop position) immediately after the wide operation in the case of wide rather than telly.

On the contrary, when the tele switch is turned on in step 1 of FIG. 3, it operates as shown in FIG.

On the contrary, when the tele switch is turned on in step 1 of FIG. 2, the operation is performed as shown in the flowchart of FIG.

At this time, as in step 3-1, the zoom motor M starts to rotate forward and rotates, and then the overtimer is operated as in step 3-2. At this time, if it is turned on by checking in step 3-3 whether the tele switch is on or not, the process proceeds to the steps of tele switch on, off check and motor stop (steps 3-3 to 3-5) depending on whether the overtimer is activated. However, if the tele switch is not on in step 3-3, the motor should be stopped. As in the case mentioned above, the deviation between the roller centers (Δh) must be corrected in the tele mode, as in the present embodiment. After the motor is rotated about 40 msec to compensate for this, that is, the lens-to-lens arrangement is rearranged to a predetermined position so that the resolution of the image obtained through this lens is not changed, and then the motor is stopped and placed in the stop position (step). 3-6 to step 3-8).

After the predetermined program according to the flowchart as described above is provided in the VTR camera system, a constant image quality is always obtained without a change in resolution when the tele or wide zoom function is operated. It is also applicable to the feeding method of the lens when fitting the PUNT.

Claims (3)

A barrel provided with a guide hole for the zoom function of the VTR camera, a roller moving along the hole in the tele or wide mode, and a lens group mounted on the roller, and the barrel rotating in response to the tele or wide mode selection. A zoom motor control method of a VTR camera including a zoom motor and a gear group for driving the control method, the method comprising: determining whether the tele mode or the wide mode is in response to the tele or wide mode selection; Driving the zoom motor in reverse rotation until the over timer is turned on or the wide switch is turned off; and if the mode is determined in the tele mode, the zoom motor is driven in the forward rotation until the over timer is turned on or the tele switch is turned off. And to compensate for the deviation between the roller centers in the guide hole after the forward rotation of the zoom motor. Zoom motor control method of a VTR camera equipped with a zoom function, characterized in that consisting of the step of rotating the zoom motor in reverse rotation. A barrel provided with a guide hole for the zoom function of the VTR camera, a roller moving along the hole according to the tele or wide mode, and a lens group mounted on the roller, and the barrel rotating in response to the tele or wide mode selection. A zoom motor control method of a VTR camera including a zoom motor and a gear group for driving the motor, the method comprising: determining whether the tele mode or the wide mode is in response to the tele or wide mode selection; If the overclock is turned on or if the wide switch is turned off, the zoom motor is driven in reverse rotation, and if the mode is determined in the tele mode, the zoom motor is rotated forward until the over timer is turned on or the tele switch is turned off. Driving and compensating for the deviation between the roller centers in the guide groove after the reverse rotation driving of the zoom motor. Zoom motor control method of a VTR camera with a zoom function, characterized in that consisting of driving the forward rotation of the zoom motor. The zoom motor control method of claim 2, wherein the forward rotation time amount for compensating for the deviation is about 40 msec.

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