JP2687896B2 - Ultra-sensitive CCD color camera device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-sensitive CCD color camera device having a night mode and a normal day mode for increasing the sensitivity by increasing the charge storage time of the CCD element.

[0002]

2. Description of the Related Art Conventionally, there is an ultra-sensitive CCD color camera device having a high-sensitivity night mode capable of shooting at night and a normal daytime mode. FIG. 4 is a block diagram of a conventional super high sensitivity CCD color camera device. 1 is a CCD element, 2 is a preamplifier that amplifies the output signal of the CCD element 1, 3 is a process circuit that performs gain adjustment, band adjustment, white level and black level adjustment, etc. on the signal output from the preamplifier 2,
5 is a memory circuit for storing the output signal of the process circuit 3,
Reference numeral 5a is an A / D converter in the memory circuit 5 for converting the output signal of the process circuit 3 into a digital signal, and 5b.
Is a memory for storing the output signal of the A / D converter 5a, 5c
Is a D / A converter for converting the signal read from the memory 5b into an analog signal.

Further, 6 is a synchronizing circuit for adding a synchronizing signal SYNC output from a synchronizing generating circuit (not shown) to an output signal of the memory circuit 5 to generate a final video signal, and 7 is a C
C for outputting various pulses for driving the CD element 1
Reference numeral 8 is a CD drive circuit, 8 is a mode switch for switching the above modes, and 9 is a control circuit for outputting a control signal for notifying the mode to the CCD drive circuit 7 according to the operation of the mode switch 8.

Next, regarding the operation of such an ultrahigh sensitivity CCD color camera device, the operation in the night mode will be described first. When the control circuit 9 detects that the mode switch 8 has been operated and the night mode is designated, the control circuit 9 outputs a control signal indicating the night mode to the CCD drive circuit 7. CCD
The drive circuit 7 changes the pulse for controlling the charge storage time of the CCD element 1 according to the control signal so that the charge storage time of the CCD element 1 changes from 0 second in the day mode to 1 in the night mode. Change to / 15 to 2 seconds.

Next, the signal output from the CCD element 1 is amplified by the preamplifier 2 and the process circuit 3 makes various adjustments as described above. The signal output from the process circuit 3 is converted into a digital signal by the A / D converter 5a of the memory circuit 5 and written in the memory 5b, and then read from the memory 5b to be D / A.
It is converted into an analog signal by the converter 5c. Then, the synchronization circuit 6 generates a final video signal from the output signal of the memory circuit 5 and outputs it to the outside.

As described above, in the night mode, the charge accumulation time of the CCD element 1 is long, and no signal is output from the CCD element 1 while the charge is accumulated. The contents thus read are repeatedly read from the memory circuit 5 so that the video signal is not interrupted. Also, the operation in the day mode is almost the same as that in the night mode except that the charge accumulation time of the CCD element 1 is different, but the contents stored in the memory circuit 5 can be read by one output of the CCD element 1. Against once.

[0007]

As described above, in the conventional super high sensitivity CCD color camera device, the output signal of the CCD element is converted into the A / D converter, the memory, and the D signal in both the day mode and the night mode. The video signal is output as a video signal through a memory circuit including an A / A converter, and these circuits are constantly operating, which causes a problem that power consumption and heat generation associated therewith are large. The present invention has been made to solve the above problems, and an object of the present invention is to provide an ultra-sensitive CCD color camera device capable of suppressing power consumption and heat generation accompanying it.

[0008]

The present invention outputs a CCD element and a pulse for driving the CCD element,
Among these pulses, the pulse that controls the charge storage time is changed according to the mode to change the charge storage time ,
Determines the signal output timing of the CCD element in daytime mode
Horizontal blanking pulse
A CCD drive circuit that delays the delay time, an A / D converter that converts the output signal of the CCD element into a digital signal, a memory that stores the output signal of this A / D converter, and a signal read from the memory D / to convert to analog signal
A memory circuit including an A converter, a synchronization circuit that adds a synchronization signal to an output signal of the memory circuit to generate a video signal, and a CCD circuit that bypasses the memory circuit in the daytime mode.
By-pass control means for directly inputting the output of the element to the synchronous circuit.

The bypass control means outputs a control signal indicating a night mode or a day mode, and C
It is provided between the CD element and the memory circuit, and between the memory circuit and the synchronization circuit, and when the control signal indicating the night mode is input, the output of the CCD element and the input of the memory circuit, and the output of the memory circuit and the synchronization circuit. It is composed of a signal changeover switch for connecting the input and directly connecting the CCD element and the synchronizing circuit when a control signal indicating the daytime mode is input .

[0010]

According to the present invention, in the night mode, the video signal is output from the synchronizing circuit by inputting the output signal of the CCD element to the synchronizing circuit via the memory circuit. Further, in the daytime mode, the memory circuit is bypassed by the bypass control means, and the output of the CCD element is directly input to the synchronizing circuit. Further, when a control signal indicating the night mode is output from the control circuit of the bypass control means, the signal changeover switch connects the output of the CCD element and the input of the memory circuit, and the output of the memory circuit and the input of the synchronous circuit, and the daytime When the control signal indicating the mode is output, the CCD element and the synchronizing circuit are directly connected. In the daytime mode, the CCD drive circuit delays the horizontal blanking pulse by the delay time of the memory circuit, so that the signal output timing of the CCD element is delayed by the delay time.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an ultra-sensitive CC according to an embodiment of the present invention.
It is a block diagram of a D color camera device, and the same components as those in FIG. 4 are denoted by the same reference numerals. Reference numeral 4 denotes a signal changeover switch, which connects the output of the CCD element 1 and the input of the memory circuit 5 and the output of the memory circuit 5 and the input of the synchronous circuit 6 when the control signal indicating the night mode is input, When the control signal indicating the mode is input, the CCD element 1 and the synchronizing circuit 6 are directly connected.

Further, 7a is a CCD drive circuit 7 in the example of FIG.
Similarly to the above, a CCD drive circuit that delays the horizontal blanking pulse φH that determines the signal output timing of the CCD element 1 in the daytime mode by the delay time by the memory circuit 5,
Reference numeral 9a denotes a control circuit that outputs a control signal indicating the night mode or the day mode according to the operation of the mode switch 8, V1 denotes a signal output from the process circuit 3, and V2 denotes a synchronization circuit 6
This is a signal output from the side signal changeover switch 4.

Next, regarding the operation of such an ultrahigh sensitivity CCD color camera device, the operation in the night mode will be described first. FIG. 2 is a timing chart for explaining the operation in the night mode, where VT is the effective period of the video signal, HBLK is the horizontal blanking period, and t is the delay time by the memory circuit 5.

When the control circuit 9a detects that the mode switch 8 has been operated and the night mode has been designated, the CCD 9c
The control signal indicating the night mode is output to the drive circuit 7a, and
In the same manner as in the above example, the charge storage time of the CCD element 1 is changed and this control signal is also output to the signal changeover switch 4. As a result, the signal changeover switch 4 is switched to the side a, and the same operation as in the example of FIG. 4 is performed.

That is, from the CCD drive circuit 7a to FIG.
The horizontal blanking pulse φH as shown in (a) is output, and the CCD element 1 outputs the horizontal blanking pulse φH.
Since the signal is output at the timing of the video signal valid period VT, the process circuit 3 outputs the signal V1 as shown in FIG. 2B. Strictly speaking, since there is a delay time due to the preamplifier 2 and the process circuit 3 between the output timing of the CCD element 1 and the timing of the process circuit 3, there is a deviation between the timings of FIGS. 2 (a) and 2 (b). Although it occurs, the delay time is considerably smaller than the delay time t of the memory circuit 5. Therefore, the delay time is illustrated as 0 here.

The output signal V1 is input to the memory circuit 5 via the signal changeover switch 4,
The memory circuit 5 outputs the output signal V2 as shown in FIG. 2C by the same operation as in the example of FIG. At this time, the signal V2 is delayed from the signal V1 by the time t due to the delay time t of the memory circuit 5. Next, the synchronization circuit 6 adds the synchronization signal SYNC output from the synchronization generation circuit (not shown) to the signal V2 input through the signal changeover switch 4, generates a video signal (not shown), and outputs the video signal to the outside. Thus,
The same operation as the night mode in the example of FIG. 4 is performed.

Next, the operation in the daytime mode will be described. FIG. 3 is a timing chart for explaining the operation in the daytime mode. However, FIGS. 3A to 3C
Is a waveform when the same horizontal blanking pulse φH as in the night mode is used. The control circuit 9a includes a mode switch 8
When is detected and the day mode is specified,
A control signal indicating the daytime mode is output to the CCD drive circuit 7a to change the charge storage time of the CCD element 1 to the daytime mode, and this control signal is also output to the signal changeover switch 4.

As a result, the signal changeover switch 4 is switched to the b side, so that the memory circuit 5 is bypassed and the output of the process circuit 3 is directly input to the synchronous circuit 6. As described above, by bypassing the unnecessary memory circuit 5 in the daytime mode, the output signal V1 of the process circuit 3 is
Is not input to the memory circuit 5, the memory circuit 5
Power consumption can be suppressed.

By the way, since the delay time t by the memory circuit 5 is eliminated by bypassing the memory circuit 5, if the horizontal blanking pulse φH (FIG. 3A) having the same timing as the night mode is used, the process circuit 3 is used. Output signal V1 of FIG. 3 and the input signal V2 of the synchronizing circuit 6 are shown in FIG.
The waveform is as shown in (c).

However, when the signal V2 shown in FIG. 3C is input to the synchronizing circuit 6, the synchronizing signal S shown in FIG.
Since the valid periods of YNC and the video signal are deviated by the time t, the period of the video signal of the signal V2 overlaps the horizontal blanking period HBLK of the synchronization signal SYNC, and a normal video signal cannot be obtained. Therefore, the CCD drive circuit 7
When a control signal indicating the day mode is output from the control circuit 9a, the horizontal blanking pulse φ shown in FIG. 3D is delayed from the timing shown in FIG. 3A by time t.
The H is output to the CCD element 1.

As a result, the timing of the signal output from the CCD element 1 is delayed by the time t, so that the output signal V1 of the process circuit 3 and the input signal V2 of the synchronizing circuit 6 are as shown in FIG.
The waveform is as shown in (e). As a result, the timing of the signal V2 is aligned with the timing of the synchronization signal SYNC, so that it is possible to generate a normal video signal.

[0022]

According to the present invention, in the daytime mode, the memory circuit is bypassed by the bypass control means to bypass the memory circuit.
Since the output of the CD element is directly input to the synchronous circuit and the output of the CCD element is not input to the memory circuit, the power consumption of the memory circuit including the A / D converter, the memory, and the D / A converter and the heat generation accompanying it Can be suppressed. Further, by configuring the bypass control means from the control circuit and the signal changeover switch, the bypass control means for bypassing the memory circuit in the daytime mode can be realized with a simple configuration.

In the daytime mode, the CCD driving circuit delays the horizontal blanking pulse by the delay time of the memory circuit, so that the signal output timing of the CCD element is delayed by the delay time. It is possible to eliminate the generated timing difference between the output signal of the CCD element and the synchronization signal.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ultra-high sensitivity CCD color camera device showing an embodiment of the present invention.

FIG. 2 is a timing chart diagram for explaining an operation in a night mode.

FIG. 3 is a timing chart diagram for explaining an operation in a daytime mode.

FIG. 4 is a block diagram of a conventional ultra-sensitive CCD color camera device.

[Explanation of symbols]

1 ... CCD element, 2 ... preamplifier, 3 ... process circuit,
4 ... Signal changeover switch, 5 ... Memory circuit, 5a ... A / D
Converter, 5b ... Memory, 5c ... D / A converter, 6 ... Synchronous circuit, 7a ... CCD drive circuit, 8 ... Mode switch, 9
a ... Control circuit.

Claims (2)

(57) [Claims] 1. Increasing the charge storage time of a CCD device
In an ultra-high-sensitivity CCD color camera device equipped with a night mode and a normal daytime mode for achieving high sensitivity for nighttime shooting , a CCD element and a pulse for driving this CCD element are output, and a pulse for driving this CCD element is output. When a pulse for controlling out the charge accumulation time varying the charge accumulation time vary depending on the mode co
And the signal output timing of CCD element in daytime mode
The horizontal blanking pulse that determines
A CCD drive circuit that delays by a delay time, and A / that converts the output signal of the CCD element into a digital signal
A memory circuit including a D converter, a memory that stores an output signal of the A / D converter, and a D / A converter that converts a signal read from the memory into an analog signal, and an output signal of the memory circuit. A synchronizing circuit that adds a synchronizing signal to generate a video signal, and a CCD that bypasses the memory circuit in the daytime mode
An ultra-high sensitivity CCD color camera device having a bypass control means for directly inputting the output of the element to a synchronizing circuit. 2. The ultra-sensitive CCD color camera device according to claim 1, wherein the bypass control means outputs a control signal indicating a night mode or a day mode, between the CCD element and the memory circuit, and the memory circuit. And a synchronous circuit, respectively, and when the control signal indicating the night mode is input, the output of the CCD element and the input of the memory circuit, and the output of the memory circuit and the input of the synchronous circuit are connected to indicate the day mode. An ultra-high-sensitivity CCD color camera device comprising a signal changeover switch for directly connecting a CCD element and a synchronizing circuit when a control signal is input.