JPH0355980A - Image pickup device with electronic telescope function - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the resolution due to an electronic telescope operation at the wide side by acting a signal processing circuit processing a photoelectric-converted electric signal into a video signal like an electronic telescope when a detection signal from a sensor at the telescope side is inputted continuously for a prescribed time or over at the input of the telescope side ON signal. CONSTITUTION:When a zoom switch 3a is depressed, a zoom lens 1 is moved to the position of the telescope and when the zoom lens 1 reaches the moving end of the telescope, a telescope side sensor 5 detects it and a detection signal S2 is outputted to other input terminal of a NOR gate 11. The NOR gate 11 outputs a signal changing from L to H to a terminal A of a monostable multivibrator circuit 12 and a terminal D of a D flip-flop 13. A timing pulse generating circuit 8 brings a signal processing circuit 7 into the electronic telescope operation and the circuit 7 outputs a video signal V magnifying the standard picture into a prescribed magnification.

Description

[Detailed Description of the Invention] Industrial field of application> The present invention relates to an image pickup device with an electronic telephoto function, such as a camera-integrated videotape recorder, which has an image enlargement function in a circuit that processes photoelectrically converted electrical signals. Regarding equipment.

BACKGROUND ART Conventionally, a camera-integrated video tape recorder (hereinafter abbreviated as VTR) as shown in FIG. 4, for example, is known as this type of imaging device with an electronic telephoto function. This camera-integrated VTR includes a zoom lens 2l driven by a motor, and a zoom lens 2l driven by a motor. By reversing the movement, the zoom lens 2l is moved to the tele side. It includes a zoom switch 23 provided on the grip section 22 for switching to the wide side, and an electronic telephoto switch 24 provided on the side of the main body. And the cameraman
When you press the electronic telephoto switch 24 while looking at the subject through the electronic viewfinder 25 on the top of the main body, the zoom lens 2l
The electrical signal of subject 0, which has been captured by an image sensor (not shown) as shown in FIG. The image is displayed in the finder 25 at a predetermined magnification (area ratio: 4 times) as shown in FIG. 5(b).

<Problems to be Solved by the Invention> However, the above-mentioned conventional camera-integrated VTR has a structure in which the cameraman manually presses the electronic telephoto switch 24 while looking through the electronic viewfinder 25, so it is easy to make an erroneous operation. If you accidentally press the electronic telephoto switch 24 while the camera is set to the wide side,
The drawback is that the resolution deteriorates and the video is difficult to view. Furthermore, if you take your eyes off the electronic viewfinder 25 to check the position of the electronic telephoto switch 24, not only will the image be shaken, but the number of switches will increase, impairing operability, which is a major advantage of this type of VTR. There's a problem.

Therefore, an object of the present invention is to detect the telephoto side moving end of the zoom lens and the turning of the zoom switch to the telephoto side, and to automatically operate the signal processing circuit for electronic telephoto operation based on the detection result, thereby eliminating image blur. To provide an imaging device with an electronic telephoto function, which can eliminate recording of images that are difficult to view due to deterioration in resolution and resolution, and can improve operability by reducing the number of switches.

Means for Solving the Problems> In order to achieve the above object, an imaging device with an electronic telephoto function of the present invention includes a zoom lens driven by a motor, and a zoom lens driven by a motor. By reversing the movement, the zoom lens is moved to the tele side. It includes a zoom switch that switches to the wide-angle side, an imaging device that converts the image information captured by the zoom lens into an electrical signal, and a signal processing circuit that processes the electrical signal into a video signal and has an electronic telephoto function that enlarges the standard image. A telephoto end detection sensor detects that the zoom lens is at the telephoto end, and a telephoto end detection sensor detects that the zoom lens is at the telephoto end, and the telephoto end detection sensor detects when the telephoto side on signal indicating that the zoom switch is switched to the telephoto side is input. The present invention is characterized by comprising an electronic telephoto switching control circuit that outputs a control signal for causing the signal processing circuit to perform electronic telephoto operation when a detection signal from the side edge detection sensor is continuously input for a predetermined period of time or longer.

Effect> When the zoom switch is switched to the telephoto side, a telephoto side ON signal is outputted from the zoom switch to the electronic telephoto switching control circuit, and the motor rotates forward, for example, to move the zoom lens to the telephoto side.

When the zoom lens reaches the telephoto end (the position of the maximum focal length of the zoom lens), the telephoto end detection sensor continuously outputs a detection signal to the electronic telephoto switching control circuit. The electronic telephoto switching control circuit performs signal processing to process the electric signal from the imaging means into a video signal when the detection signal from the telephoto end detection sensor is continuously input for a predetermined time or more when the telephoto side ON signal is input. A control signal is outputted to the circuit to cause the signal processing circuit to perform electronic telephoto operation. Then, the signal processing circuit enlarges the standard image to a predetermined magnification and outputs it as a video signal to the built-in VTR or external equipment. Therefore, if the zoom switch is set to the wide-angle side or if the zoom lens does not stop at the telephoto end for a predetermined period of time with the zoom switch set to the telephoto side, the signal processing circuit will not operate the electronic telephoto mode. Also, the resolution does not deteriorate due to electronic telephoto operation on the wide side.

Example Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a block diagram showing a camera-integrated VTR which is an embodiment of the present invention. 3 is a zoom lens driven by a motor 2 via a gear, and 3 is a positive lens of the motor 2 via a motor drive circuit 4. A zoom switch that switches the movement of the zoom lens l between the telephoto side 3a and the wide side 3b by reversing the rotation; 5 is a telephoto end detection sensor that detects the telephoto end of the zoom lens 1 (the position of the maximum focal length of the zoom lens); 6 is an image sensor that converts image information captured by the zoom lens l into an electrical signal.

Further, 7 is a signal processing circuit having an electric telephoto function for processing the electric signal into a video signal V and enlarging a standard image, and 8 is a timing for supplying various timing pulses necessary to the image pickup device 6 and the signal processing circuit 7. A pulse generation circuit 9 generates a detection signal S, 1 "L" from the telephoto end detection sensor when a telephoto side ON signal S1 = "L" indicating that the telephoto side 3a of the zoom switch 3 is on is input. This is an electronic telephoto switching control circuit which outputs a control signal S3=“H” via the timing pulse generating circuit 8, which causes the signal processing circuit 7 to perform an electronic telephoto operation when the signal is continuously input for a predetermined time or more.

The telephoto side edge detection sensor 5 is of a mechanical contact type or an optical type such as a reflective photointerrupter, and detects the telephoto side moving end of the zoom lens l and outputs a detection signal S,=“L”. Output. In the zoom switch 3, the tele side 3a and wide side 3b are not turned on at the same time, and when the tele side 3a is turned on, the tele side on signal SI = "
Note that the blocks other than the telephoto end detection sensor 5 and the electronic telephoto switching control circuit 9 are the same as those provided in the conventional example described in FIG. 4.

FIG. 2 is a detailed block diagram showing an example of the configuration of the electronic telephoto switching control circuit 9. As shown in FIG. This control circuit 9 includes a NOR gate 1l that takes the logical sum of the tele side ON signal SI and the detection signal S, and inverts the result, and receives the output of this NOR gate as a trigger signal at an input terminal A, so that an output signal Q becomes "L". A power supply voltage Vcc is applied to the T terminal via a capacitor C and a resistor R that determines the time constant TII+, and the input terminals B,
Monostable multivibrator I with Vcc applied to CD
2, the output Q of this monostable multivibrator l2 is received at the clock input terminal OK, the output of the NOR gate l1 is received at the human power terminal D and the clear terminal CL, and the input terminal P
It consists of a D-flip-flop 13 to which Vcc is applied to R and outputs the control signal S3 from the output terminal Q to the timing pulse generation circuit 8. Note that the above time constant Tm is Tm#0.72XCXR (seconds).

The operation of the camera-integrated VTR having the above configuration will be described below with reference to FIG. 3, focusing on the electronic telephoto switching control circuit 9 shown in FIG.

First, at time 70, the zoom switch 3a on the tele side
is not pressed, and the tele side on signal SI is as shown in Fig. 3 (a).
) is at "H" level. Next, when the zoom switch 3a is pressed down at time t, the Noah gate 1! of the control circuit 9 is pressed down. At the same time, the "L" level telephoto side ON signal Sl is outputted to one input terminal of the camera (see FIG. 3(a)), and the motor 2 is caused to rotate forward through the motor drive circuit 4, and the zoom lens l is rotated in the normal direction. Start moving to the tele side. Then, when the zoom lens l reaches the telephoto side moving end at time t, the telephoto side end detection sensor 5 detects this and changes to "L".
Level detection signal S! is outputted to the other input terminal of the NOR gate 11 as shown in FIG. 3(b). Both input terminals “
The NOR gate 11 that received the signal at the L” level operates as shown in FIG.
A signal that changes from "L" to "H" as shown in c) is output to the terminal A of the monostable multivibrator l2 and the terminal D of the D-flip-flop l3. Multi-viprator l2 is
It is triggered by the rising edge of the above signal, and the output Q is inverted from the normal “H” to “H” as shown in Figure 3(d).
It becomes L” level.

The multivibrator 12 which has inverted the output Q raises its output Q to the normal "H" level when the time constant TWl has elapsed and reaches time t, and this signal is sent to the D-flip-flop 13. It is added to the clock input terminal CK. At this time, if the tele side ON signal S1 and the detection signal St are still at the "L" level, the "H" level output of the NOR gate II is output from the input terminal D at the rising edge of the above signal.
is latched by the D-flip-flop l3, and a control signal S3 of "H" level as shown in FIG. 3(e) is sent from the output terminal Q to the timing pulse generating circuit 8 (see FIG. 1).
is output to. Then, the timing pulse generation circuit 8 that receives this control signal S3 causes the signal processing circuit 7 to perform electronic telephoto operation, and the standard image shown in FIG. 5(b) is enlarged to a predetermined time. A video signal V as shown in FIG.

After that, at time t4, the zoom switch 3a on the tele side
is turned off, the detection signal S of the telephoto end detection sensor 5
! is still at “L” level, but the tele side on signal S1 is “I” level.
1" level, and the output of NOR gate 11 becomes "L" level. This "L" level output is input to the clear terminal CL as well as the input terminal D of the D-flip-flop l3. The control signal S3 from the output terminal Q of l3 is set to "L" which disables electronic telephoto operation.
" level (see Figures 3 (a) to (e)), and the image returns from the enlarged image in Figure 5 (b) to the standard image in Figure 5 (a). Furthermore, at time t4, the zoom switch is Even when the telephoto side 3a of 3 is turned off and the wide side 3b is turned on and the zoom lens 1 is moved to the opposite wide side by reversing the motor 2, the detection signal S of the telephoto side edge detection sensor 5 is “
Since the telephoto side ON signal S1 changes to "H" and the output of the NOR gate II changes to "L", the control signal S3 becomes "L" indicating that the electronic telephoto is not operated as described above.

On the other hand, at time t, the telephoto end of the zoom lens l is detected in the same manner as at time t, the output of the Noah gate 2 becomes "H", and the monostable multivibrator l2
When the output Q changes to "L°," the telephoto side 3 of the zoom lens 3 changes at time t6 before time t7, which corresponds to the time constant T-.
If a is turned off, the D input terminal is already at the "L" level when the clock Q is input to the D-flip-flop I3, so the control signal S3 at the "H" level is not output from the output terminal Q, and the image is The standard shown in Figure 5(a) remains.

In this way, according to the embodiment described above, when the telephoto side 3a of the zoom switch 3 is off, the wide side 3b is on, or the telephoto side 3a of the zoom switch 3 is on, the zoom lens! If the camera does not stop at the telephoto side moving end (5) for a predetermined time Tm or more, the signal processing circuit 7 does not operate the electronic telephoto operation.
The resolution does not deteriorate due to electronic telephoto operation on the wide side as in the conventional case, and good recording can be performed on a VTR. Also, if you don't need electronic telephoto at the telephoto side moving end,
When the telephoto side 3a of the zoom switch is turned off, the signal processing circuit 7 is automatically activated by the electronic telephoto switching control circuit 9, so that the electronic telephoto operation can be automatically performed from the electronic viewfinder 25 as in the case of conventional manual operation. There is no need to take your eyes off to press the switch, so there is no image blur. Furthermore, the design does not require an electronic telephoto switch. It is advantageous in terms of manufacturing cost and can significantly improve operability.

It goes without saying that the present invention is not limited to the illustrated embodiment.

Effects of the Invention> As is clear from the above description, the electronic telephoto function-equipped imaging device of the present invention detects with the telephoto side end detection sensor that the zoom lens driven by the motor is at the telephoto side moving end. , motor positive. By reversing the movement, the zoom lens is moved to the tele side. Switch to the wide side When the telephoto side ON signal indicating that the zoom switch is switched to the telephoto side is input, and the detection signal from the telephoto side edge detection sensor is continuously input for a predetermined time or more, the electronic telephoto switching control is activated. The signal processing circuit that outputs a control signal from the circuit and processes the photoelectrically converted electrical signal into a video signal automatically operates electronic telephoto, so it is possible to operate electronic telephoto at the wide-angle side, unlike conventional electronic telephoto operation. There is no deterioration in resolution, there is no need to take your eyes off the electronic viewfinder and press the electronic telephoto switch, so you can record well without image shake, and the reduced number of switches makes the configuration simple and inexpensive. In addition, the operability of the device can be significantly improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a camera-integrated VTR which is an embodiment of the present invention, Fig. 2 is a detailed block diagram of the electronic telephoto switching control circuit shown in Fig. 1, and Fig. 3 is an operation of the control circuit shown in Fig. 2. A diagram showing the timing, Figure 4 is a conventional camera-integrated VTR
FIG. 5 is a diagram showing images during standard and electronic telephoto shooting. 1...Zoom lens, 2...Motor, 3...Zoom switch, 3a...Tele side, 3b...Wide side,
5...Tele side edge detection sensor, 6...Image sensor, 7.
...Signal processing circuit, 9...Electronic telephoto switching control circuit, S1...Tele side on signal, S1...Detection signal, S,...
··Control signal. Patent applicant: Sharp Corporation Agent
One patent attorney: Haka Aoyama! Figure l Figure 4 Figure 25 23 Figure 5 (a) (b)

Claims (1)

[Claims] (1) A zoom lens driven by a motor, a zoom switch that switches the movement of the zoom lens between the telephoto side and the wide side by rotating the motor forward and backward, and an imaging means that converts image information captured by the zoom lens into electrical signals. and, in an imaging device with an electronic telephoto function, which is equipped with a signal processing circuit having an electronic telephoto function that processes the electric signal into a video signal and enlarges a standard image, detecting that the zoom lens is at a telephoto side moving end. When the detection signal from the tele side edge detection sensor is continuously input for a predetermined period or more when the tele side on signal indicating that the zoom switch is switched to the tele side is inputted to the tele side edge detection sensor, the above An imaging device with an electronic telephoto function, comprising an electronic telephoto switching control circuit that outputs a control signal for operating electronic telephoto to a signal processing circuit.