Aloqa kanali

Controls Boshqaruv

Receivers are commonly provided with manual controls for adjustment of the picture by the viewer. These controls are (1) the channel switch, which connects the required circuits to the radio-frequency amplifier and superheterodyne mixer to amplify and convert the sound and picture carriers of the desired channel; (2) a fine-tuning control, which precisely adjusts the superheterodyne mixer so that the response of the tuner is exactly centred on the channel in use; (3) a contrast control, which adjusts the voltage level reached by the picture signal in the video amplifiers, producing a picture having more or less contrast (greater or less range between the blacks and whites of the image); (4) a brightness control, which adjusts the average amount of current taken by the picture tube from the high-voltage power supply, thus varying the overall brightness of the picture; (5) a horizontal-hold control, which adjusts the horizontal deflection generator so that it conforms exactly to the control of the horizontal synchronizing impulses; (6) a vertical-hold control, which performs the same function for the vertical deflection generator; (7) a hue (or “tint”) control, which shifts all the hues in the reproduced image; and (8) a saturation (or “colour”) control, which adjusts the magnitudes of the colour-difference signals applied to the electron guns of the picture tube. If the saturation control is turned to the “off” position, no colour difference action will occur and the reproduction will appear in black and white. As the saturation control is advanced, the colour differences become more accentuated, and the colours become progressively more vivid.

Qabul qiluvchilar odatda tomoshabin tomonidan tasvirni sozlash uchun qo'lda boshqaruv elementlari bilan ta'minlangan. Bu boshqaruv elementlari (1) kerakli kanalni ovoz va tasvir tashuvchilarni kuchaytirish va aylantirish uchun radiochastota kuchaytirgich va superheterodin mikseriga kerakli sxemalarni ulaydigan kanal kaliti; (2) nozik sozlash boshqaruvi, superheterodin mikserini aniq sozlaydi, shunda tyunerning javobi ishlatilayotgan kanalga to'liq mos tushadi; (3) video kuchaytirgichlarda tasvir signali erishgan kuchlanish darajasini sozlaydigan kontrastni boshqarish, ko'proq yoki kamroq kontrastga ega bo'lgan tasvirni (tasvirning qora va oq ranglari o'rtasida katta yoki kamroq diapazon) hosil qiladi; (4) yuqori kuchlanishli quvvat manbaidan rasm trubkasi tomonidan olingan oqimning o'rtacha miqdorini moslashtiradigan yorqinlikni boshqarish, shu bilan rasmning umumiy yorqinligini o'zgartiradi; (5) gorizontal burilish generatorini gorizontal sinxronlash impulslarini boshqarishga to'liq mos keladigan tarzda sozlaydigan gorizontal ushlab turish boshqaruvi; (6) vertikal burilish generatori uchun bir xil funktsiyani bajaradigan vertikal ushlab turish boshqaruvi; (7) reproduktsiya qilingan tasvirdagi barcha ranglarni o'zgartiruvchi rang (yoki "ton") boshqaruvi; va (8) rasm naychasining elektron qurollariga qo'llaniladigan rang farqi signallarining kattaligini sozlaydigan to'yinganlik (yoki "rang") boshqaruvi. Agar to'yinganlik nazorati "o'chirilgan" holatiga aylantirilsa, rang farqi harakati sodir bo'lmaydi va reproduktsiya qora va oq rangda paydo bo'ladi. Toʻyinganlikni boshqarish rivojlangan sari ranglar farqlari koʻproq taʼkidlanadi va ranglar tobora jonliroq boʻladi.

Since the late 1960s, colour television receivers have employed a system known as “automatic hue control.” In this system, the viewer makes an initial manual adjustment of the hue control to produce the preferred flesh tones. Thereafter, the hue control circuit automatically maintains the preselected ratio of the primary colours corresponding to the viewer’s choice. Thus, the most critical aspect of the colour rendition, the appearance of the faces of the performers, is prevented from changing when cameras are switched from scene to scene or when the receiver is tuned from one broadcast to another. Another enhancement is a single touch-button control that sets the fine tuning and also adjusts the hue, saturation, contrast, and brightness to preset ranges. These automatic adjustments override the settings of the corresponding separate controls, which then function over narrow ranges only. Such refinements permit reception of acceptable quality by viewers who might otherwise be confused by the many maladjustments possible when ordinary manual controls are used.

Modern remote controls, employing infrared radiation to send signals to the receiver, are descended from earlier models of the 1950s and ’60s that used electric wire, visible light, or ultrasound to control the power, channel selection, and audio volume. Today’s television sets have no knobs; instead, their features are controlled through on-screen displays of parameters that are adjusted by the remote control.
1960-yillarning oxiridan boshlab rangli televizor qabul qiluvchilar "avtomatik rangni boshqarish" deb nomlanuvchi tizimdan foydalandilar. Ushbu tizimda tomoshabin afzal qilingan tana ohanglarini ishlab chiqarish uchun rangni boshqarishni dastlabki qo'lda sozlashni amalga oshiradi. Shundan so'ng, rangni boshqarish sxemasi tomoshabin tanloviga mos keladigan asosiy ranglarning oldindan tanlangan nisbatini avtomatik ravishda saqlaydi. Shunday qilib, ranglarni ko'rsatishning eng muhim jihati, ijrochilarning yuzlarining ko'rinishi kameralar sahnadan sahnaga o'tkazilganda yoki qabul qiluvchi bir translyatsiyadan ikkinchisiga sozlanganda o'zgarishining oldini oladi. Yana bir yaxshilanish - bu nozik sozlashni o'rnatadigan, shuningdek, rang, to'yinganlik, kontrast va yorqinlikni oldindan belgilangan diapazonlarga moslashtiradigan bitta sensorli tugmachani boshqarish. Ushbu avtomatik sozlashlar tegishli alohida boshqaruv elementlarining sozlamalarini bekor qiladi, keyin ular faqat tor diapazonlarda ishlaydi. Bunday takomillashtirishlar oddiy qo'lda boshqarish vositalaridan foydalanilganda yuzaga kelishi mumkin bo'lgan ko'plab noto'g'ri sozlamalardan adashtirishi mumkin bo'lgan tomoshabinlar tomonidan maqbul sifatni qabul qilishga imkon beradi.
Qabul qiluvchiga signal yuborish uchun infraqizil nurlanishdan foydalanadigan zamonaviy masofadan boshqarish pultlari 1950 va 60-yillarning oldingi modellaridan kelib chiqqan bo'lib, ular quvvat, kanal tanlash va ovoz balandligini boshqarish uchun elektr simi, ko'rinadigan yorug'lik yoki ultratovushdan foydalangan. Bugungi televizorlarda hech qanday tugma yo'q; Buning o'rniga, ularning xususiyatlari masofadan boshqarish pulti tomonidan sozlangan parametrlarning ekrandagi displeylari orqali boshqariladi.