JPS60123171A - Video camera device - Google Patents

Abstract

PURPOSE:To prolong a service life of an image pickup tube by confirming in advance whether or not the deterioration of picture quality will occur and by elevating a target voltage in advance if the deterioration of picture quality is close at hand. CONSTITUTION:A voltage impressed on a target of an image pickup tube 101 is set to an ESJOP by a target voltage setting part 102 at time T=0, and includes a certain voltage difference of an image pickup film deterioration boundary voltage ESJG. At time T=T1a, a target voltage change operating part 202 is operated, a voltage DELTAV1 is generated from a target voltage change part 103, and a voltage of the setting part 102 is decreased by the DELTAV1. At this time, if the ESJG is higher than the value of the ESJOP-DELTAV1, picture quality deterioration due to the deterioration of the image pickup film can be recognized by watching a screen of a monitor provided. In this case, the setting part 102 is controlled through a variable part 201 at time T=T1b, and a target voltage impressed on the image pickup tube 101 is elevated by DELTAV1T. Thus the time when picture quality deterioration occurs at time T=TA can be postponded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a video camera device using an image pickup tube.

Conventional configuration and its problems The target voltage of the image pickup tube is a certain voltage (EsJm, I)
If the voltage is lower than this, a seizure phenomenon will occur, so the voltage is set to several volts higher than this EsJ (5 TOP).

However, the voltage applied to the target is another voltage lower than 81m1n, that is, the imaging film deterioration boundary voltage (ES
JG) As a result of experiments, it was found that when the temperature is below, the imaging film deteriorates and the image quality deteriorates. And this voltage E
SJG has the property of moving up the ranks over time. Therefore, if the voltages ES and TOP are left at their initial values, ESJOP-ESJG may occur, and the image quality deteriorates, making it unusable as a video camera.

OBJECTS OF THE INVENTION The present invention improves the above-mentioned problems of the conventional art.
After setting it to OP and after a long period of time has elapsed, the target voltage is raised slightly to - in order to avoid becoming unusable due to image quality deterioration due to an increase in ESJG, so that it can withstand even longer practical operation. It is something to do.

Structure of the Invention In order to achieve the above object, the present invention reduces the target voltage for a short fixed period of time, and prevents the occurrence of image quality deterioration in advance.
The system recognizes whether or not this has occurred in a short period of time, and increases the target voltage in advance if image quality deterioration is imminent.

DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 101 is an image pickup tube, 102 is a target voltage setting section, 103 is a target voltage changing section, 201 is a target electric F:fi setting variable section, and 202 is a target voltage changing operation section.

401 is a signal extraction capacitor. FIG. 2 still shows the time variation of the target voltage and the voltage "SJG".

In the above configuration, at time T=o, the target voltage setting unit 102 sets the voltage applied to the target of the image pickup tube 101 to ESJOP, and this voltage Esl0P
has a certain voltage difference from ESJG. Time T-T,
Operate the target voltage change operation section 202 at the time of a,
A voltage of Δ■1 is generated from the target voltage changing unit 103, and the voltage of the target voltage setting unit 102 is decreased by Δv1. At this time, ES than (ESJOP-Δv1)
If the JG is high, it can be recognized by viewing the image on an attached monitor (not shown) that image quality has deteriorated due to deterioration of the imaging film. In this case, time T,=T
1°, the target voltage setting variable unit 201 operates the target voltage setting unit 102'i to change the target voltage applied to the image pickup tube 101 to Δ■
Increase by 1T. This makes the target voltage E
It is possible to extend the time for image quality deterioration that occurs at time T-TA in the case of SJOP change.

Furthermore, at time T = T2a, the target voltage change operation section 202 is operated to decrease the voltage of the target voltage setting section 102 by ΔV2 as in the case described above, and if image quality deterioration has occurred, the target voltage change operation section 202 is operated to reduce the voltage of the target voltage setting section 102 by ΔV2 at time T = T2b. The voltage setting variable section 201 further increases the target voltage by Δv.
By increasing the image quality by 2T, it is possible to further extend the time required for image quality deterioration. Hereinafter, similar operations are performed after time T3a.

Note that the target voltage change operation unit 202 in FIG. 2 is replaced with the configuration of an oscillation unit 302 and a timer 301 as shown in FIG. It is also possible to reduce the target voltage by operating the target voltage setting variable section 2C) 1'fr: If the image quality is degraded by viewing the monitor, operate the target voltage setting variable section 2C) 1'fr: 102 increases the target voltage.

Effects of the Invention As is clear from the above explanation, according to the present invention, it is checked in advance whether or not image quality deterioration is likely to occur, and if image quality deterioration is imminent, the target voltage is increased in advance. It can extend the life of the image pickup tube and is useful in practice.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a video camera device according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing changes in target voltage over time, and FIG. 3 is a block diagram of another embodiment of the present invention. 101... Image tube, 1o2! ...Target voltage setting section, 103...Target voltage changing section, 201...Target voltage setting variable section, 2
02...Target voltage change operation unit, 401...Signal extraction capacitor, 301...
...Timer, 302...Oscillation section. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 1θ? ρI? ρ2 Figure 2 Figure 3 01

Claims (1)

[Claims] a target voltage setting section for applying a target voltage to the image pickup tube; a means for lowering the target voltage by a predetermined voltage when the image pickup tube is operated for a predetermined time; A video camera device comprising means for increasing voltage.