The TFT-LCD liquid crystal display is a thin film transistor type liquid crystal display, also known as "true color" (TFT). TFT liquid crystal has a semiconductor switch for each pixel, and each pixel can be directly controlled by dot pulses, so each node is relatively independent and can be continuously controlled, which not only improves the response speed of the display screen, but also can be accurately controlled Display color gradation, so the color of TFT liquid crystal is more real. TFT liquid crystal display screens are characterized by good brightness, high contrast, strong layering, and bright colors, but they also have the disadvantages of relatively power consumption and high cost.
TFT (Thin Film Transistor) is a thin film field effect transistor, which is a type of active matrix liquid crystal display. It can "actively" control each individual pixel on the screen, which can greatly improve the response time. Generally, the response time of TFT is relatively fast, about 80 milliseconds, and the viewing angle is large, generally reaching about 130 degrees.
Μέθοδος μετατροπής πολικότητας οθόνης TFT LCD:
The driving voltage of the liquid crystal molecules cannot be fixed at a certain value, otherwise, over time, the liquid crystal molecules will undergo polarization and gradually lose their optical rotation characteristics. Therefore, in order to avoid the destruction of the characteristics of the liquid crystal molecules, the driving voltage of the liquid crystal molecules must be polarized. This requires the display voltage in the liquid crystal display to be divided into two polarities, one is positive polarity and the other is negative polarity. . When the voltage of the display electrode is higher than the voltage of the common electrode, it is called positive polarity; when the voltage of the display electrode is lower than the voltage of the common electrode, it is called negative polarity. Regardless of the positive polarity or the negative polarity, there will be a set of gray scales with the same brightness, so when the absolute value of the pressure difference between the upper and lower glass layers is fixed, the gray scales displayed are exactly the same. However, in these two cases, the turning of the liquid crystal molecules is completely opposite, which can avoid the above-mentioned characteristic damage caused when the turning of the liquid crystal molecules is always fixed in one direction. There are four common polarity conversion methods, namely frame-by-frame phase inversion, line-by-line phase inversion, column-by-column phase inversion, and point-by-point phase inversion.
For the frame-by-frame phase inversion mode, in the same frame, all adjacent points in the entire screen have the same polarity, while the adjacent frame polarities are different; for the line-by-line phase inversion mode, the same polarity is on the same line. Polarity, and the adjacent rows have different polarities; for the column-by-column phase inversion mode, the same polarity is on the same column, while the adjacent columns have different polarities; for the point-by-point phase inversion mode, each point The polarities of the four points up, down, left, and right adjacent to oneself are all different.
At present, the common LCD screens of personal computers, most of the panel polarity conversion methods used are point-by-point conversion methods. Why? The reason is that the display quality of point-by-point phase inversion is much better than other conversion methods. The table lists the performance comparison of the four polarity conversion modes: frame-by-frame phase inversion, line-by-line phase inversion, column-by-column phase inversion, and point-by-point phase inversion.
Το λεγόμενο-φαινόμενο Flicker είναι ότι η οθόνη θα αισθάνεται ότι τρεμοπαίζει, αλλά δεν είναι ένα σκόπιμα οπτικό εφέ, αλλά επειδή η κλίμακα του γκρι της εμφανιζόμενης οθόνης θα αλλάζει ελαφρώς κάθε φορά που ενημερώνεται η οθόνη, κάνοντας τους ανθρώπους να αισθάνονται ότι η οθόνη τρεμοπαίζει. . Αυτή η κατάσταση είναι πολύ πιθανό να συμβεί χρησιμοποιώντας τη μέθοδο μετατροπής πολικότητας της αντιστροφής φάσης καρέ-από-καρέ. Επειδή ολόκληρη η εικόνα του πλαισίου-ανά-αναστροφή καρέ έχει την ίδια πολικότητα, όταν αυτή τη φορά η εικόνα είναι θετική, την επόμενη φορά θα είναι αρνητική. Εάν υπάρχει ένα μικρό σφάλμα στην κοινή τάση, τότε η θετική και η αρνητική πολικότητα θα είναι η ίδια κλίμακα του γκρι. Θα υπάρχει διαφορά στην τάση και φυσικά η κλίμακα του γκρι έχει διαφορετική αίσθηση, όπως φαίνεται στο Σχήμα 2. Στην περίπτωση που οι οθόνες αλλάζουν συνεχώς, θα εμφανιστεί το φαινόμενο Flicker λόγω της εναλλακτικής εμφάνισης θετικών και αρνητικών οθονών. Η μέθοδος μετατροπής πολικότητας άλλων πάνελ, αν και θα υπάρχει αυτό το φαινόμενο Flicker, αλλά επειδή σε αντίθεση με την αντιστροφή φάσης-από-καρέ, η πολικότητα ολόκληρης της οθόνης αλλάζει ταυτόχρονα. Υπάρχει μόνο μία γραμμή ή μία στήλη και ακόμη και ένα σημείο αλλάζει την πολικότητα. Όσον αφορά το ανθρώπινο μάτι, δεν θα είναι εμφανές.
The so-called Crosstalk phenomenon refers to that between adjacent points, the data to be displayed will affect the other party, so that the displayed screen will be incorrect. Although there are many causes of the Ctosstalk phenomenon, as long as the polarities of adjacent points are different, the occurrence of this phenomenon can be reduced.
Η αρχή λειτουργίας της οθόνης υγρών κρυστάλλων TFT:
How TFT works TFT is the abbreviation of "Thin Film Transistor", generally refers to thin film liquid crystal displays, but actually refers to thin film transistors (matrix)-can "actively" on the screen of each independent pixel Control, this is the origin of the so-called active matrix TFT (active matrix TFT). So how exactly is the image produced? The basic principle is very simple: the display screen is composed of many pixels that can emit light of any color, and the goal can be achieved by controlling each pixel to display the corresponding color. In TFTLCD, backlight technology is generally used. In order to accurately control the color and brightness of each pixel, it is necessary to install a shutter-like switch after each pixel. When the "blinds" are opened, light can pass through, and the "blinds" "When it is closed, the light cannot pass through. Of course, technically, it is not as simple as the one just mentioned.
LCD (Liquid Crystal Display) uses the characteristics of liquid crystals (liquid when heated, and crystallized into solid when cooled). Generally, liquid crystals have three forms:
Smectic liquid crystal similar to clay
Nematic liquid crystal resembling a fine matchstick
Cholestic liquid crystal
The liquid crystal display uses filaments, and when the external environment changes, its molecular structure will also change, and thus have different physical properties-it can achieve the purpose of letting light through or blocking light-which is just like the blinds just now.
Everyone knows the three primary colors, so each pixel on the display screen needs three similar basic components described above to control the three colors of red, green, and blue respectively.
The most commonly used one is twisted nematic TFT LCD (Twisted Nematic TFT LCD). The following figure explains the working principle of this type of TFT LCD. The existing technologies vary greatly, and we will cover them in detail in the second part of this article.
Υπάρχουν αυλακώσεις στο άνω και κάτω στρώμα. Οι αυλακώσεις στο ανώτερο στρώμα είναι διατεταγμένες κατά μήκος και οι αυλακώσεις στο κάτω στρώμα διατάσσονται οριζόντια. Το κάτω στρώμα είναι διατεταγμένο οριζόντια. Όταν δεν εφαρμόζεται τάση, ο υγρός κρύσταλλος βρίσκεται σε φυσική κατάσταση και το φως που εκπέμπεται από το διάγραμμα αρχής λειτουργίας της στριμμένης νηματικής οθόνης TFT στο Σχήμα 2α μετά τη διέλευση από το ενδιάμεσο στρώμα θα συστραφεί κατά 90 μοίρες, έτσι ώστε να μπορεί να περάσει μέσω του κάτω στρώματος ομαλά.
When a voltage is applied between the two layers, an electric field is generated. At this time, the liquid crystals are aligned vertically, so the light will not be twisted-the result is that the light cannot pass through the lower layer.
TF:
Color filters are divided into three types: red, green and blue according to their colors. They are arranged on the glass substrate to form a group (dot pitch) corresponding to a pixel. Each monochromatic filter is called a sub{{0}}pixel (sub-pixel). ). In other words, if a TFT display supports a maximum resolution of 12801024, then at least 128031024 sub-pixels and transistors are required. For a 15-inch TFT display (1024768), then a pixel is about 0.0188 inches (equivalent to 0.30mm), for an 18.1-inch TFT display (12801024), it is 0.011 inches (equivalent to 0.28mm) As we all know, pixels are decisive for the display, and the smaller each pixel is, the larger the maximum resolution that the display can achieve. However, due to the limitation of the physical characteristics of transistors, the current size of each pixel of TFT is basically 0.0117 inches (0.297mm), so for a 15-inch display, the maximum resolution is only 12801024.
Μέθοδος μετατροπής πολικότητας οθόνης TFT LCD:
The driving voltage of the liquid crystal molecules cannot be fixed at a certain value, otherwise, over time, the liquid crystal molecules will undergo polarization and gradually lose their optical rotation characteristics. Therefore, in order to avoid the destruction of the characteristics of the liquid crystal molecules, the driving voltage of the liquid crystal molecules must be polarized. This requires the display voltage in the liquid crystal display to be divided into two polarities, one is positive polarity and the other is negative polarity. . When the voltage of the display electrode is higher than the voltage of the common electrode, it is called positive polarity; when the voltage of the display electrode is lower than the voltage of the common electrode, it is called negative polarity. Regardless of the positive polarity or the negative polarity, there will be a set of gray scales with the same brightness, so when the absolute value of the pressure difference between the upper and lower glass layers is fixed, the gray scales displayed are exactly the same. However, in these two cases, the turning of the liquid crystal molecules is completely opposite, which can avoid the above-mentioned characteristic damage caused when the turning of the liquid crystal molecules is always fixed in one direction. There are four common polarity conversion methods, namely frame-by-frame phase inversion, line-by-line phase inversion, column-by-column phase inversion, and point-by-point phase inversion.
For the frame-by-frame phase inversion mode, in the same frame, all adjacent points in the entire screen have the same polarity, while the adjacent frame polarities are different; for the line-by-line phase inversion mode, the same polarity is on the same line. Polarity, and the adjacent rows have different polarities; for the column-by-column phase inversion mode, the same polarity is on the same column, while the adjacent columns have different polarities; for the point-by-point phase inversion mode, each point The polarities of the four points up, down, left, and right adjacent to oneself are all different.
At present, the common LCD screens of personal computers, most of the panel polarity conversion methods used are point-by-point conversion methods. Why? The reason is that the display quality of point-by-point phase inversion is much better than other conversion methods. The table lists the performance comparison of the four polarity conversion modes: frame-by-frame phase inversion, line-by-line phase inversion, column-by-column phase inversion, and point-by-point phase inversion.
Το λεγόμενο-φαινόμενο Flicker είναι ότι η οθόνη θα αισθάνεται ότι τρεμοπαίζει, αλλά δεν είναι ένα σκόπιμα οπτικό εφέ, αλλά επειδή η κλίμακα του γκρι της εμφανιζόμενης οθόνης θα αλλάζει ελαφρώς κάθε φορά που ενημερώνεται η οθόνη, κάνοντας τους ανθρώπους να αισθάνονται ότι η οθόνη τρεμοπαίζει. . Αυτή η κατάσταση είναι πολύ πιθανό να συμβεί χρησιμοποιώντας τη μέθοδο μετατροπής πολικότητας της αντιστροφής φάσης καρέ-από-καρέ. Επειδή ολόκληρη η εικόνα του πλαισίου-ανά-αναστροφή καρέ έχει την ίδια πολικότητα, όταν αυτή τη φορά η εικόνα είναι θετική, την επόμενη φορά θα είναι αρνητική. Εάν υπάρχει ένα μικρό σφάλμα στην κοινή τάση, τότε η θετική και η αρνητική πολικότητα θα είναι η ίδια κλίμακα του γκρι. Θα υπάρχει διαφορά στην τάση και φυσικά η κλίμακα του γκρι έχει διαφορετική αίσθηση, όπως φαίνεται στο Σχήμα 2. Στην περίπτωση που οι οθόνες αλλάζουν συνεχώς, θα εμφανιστεί το φαινόμενο Flicker λόγω της εναλλακτικής εμφάνισης θετικών και αρνητικών οθονών. Η μέθοδος μετατροπής πολικότητας άλλων πάνελ, αν και θα υπάρχει αυτό το φαινόμενο Flicker, αλλά επειδή σε αντίθεση με την αντιστροφή φάσης-από-καρέ, η πολικότητα ολόκληρης της οθόνης αλλάζει ταυτόχρονα. Υπάρχει μόνο μία γραμμή ή μία στήλη και ακόμη και ένα σημείο αλλάζει την πολικότητα. Όσον αφορά το ανθρώπινο μάτι, δεν θα είναι εμφανές.
The so-called Crosstalk phenomenon refers to that between adjacent points, the data to be displayed will affect the other party, so that the displayed screen will be incorrect. Although there are many causes of the Ctosstalk phenomenon, as long as the polarities of adjacent points are different, the occurrence of this phenomenon can be reduced.
Η αρχή λειτουργίας της οθόνης υγρών κρυστάλλων TFT:
How TFT works TFT is the abbreviation of "Thin Film Transistor", generally refers to thin film liquid crystal displays, but actually refers to thin film transistors (matrix)-can "actively" on the screen of each independent pixel Control, this is the origin of the so-called active matrix TFT (active matrix TFT). So how exactly is the image produced? The basic principle is very simple: the display screen is composed of many pixels that can emit light of any color, and the goal can be achieved by controlling each pixel to display the corresponding color. In TFTLCD, backlight technology is generally used. In order to accurately control the color and brightness of each pixel, it is necessary to install a shutter-like switch after each pixel. When the "blinds" are opened, light can pass through, and the "blinds" "When it is closed, the light cannot pass through. Of course, technically, it is not as simple as the one just mentioned.
LCD (Liquid Crystal Display) uses the characteristics of liquid crystals (liquid when heated, and crystallized into solid when cooled). Generally, liquid crystals have three forms:
Cholestic liquid crystal
Nematic liquid crystal resembling a fine matchstick
Smectic liquid crystal similar to clay
The liquid crystal display uses filaments, and when the external environment changes, its molecular structure will also change, and thus have different physical properties-it can achieve the purpose of letting light through or blocking light-which is just like the blinds just now.
Everyone knows the three primary colors, so each pixel on the display screen needs three similar basic components described above to control the three colors of red, green, and blue respectively.
The most commonly used one is twisted nematic TFT LCD (Twisted Nematic TFT LCD). The following figure explains the working principle of this type of TFT LCD. The existing technologies vary greatly, and we will cover them in detail in the second part of this article.
Υπάρχουν αυλακώσεις στο άνω και κάτω στρώμα. Οι αυλακώσεις στο ανώτερο στρώμα είναι διατεταγμένες κατά μήκος και οι αυλακώσεις στο κάτω στρώμα διατάσσονται οριζόντια. Το κάτω στρώμα είναι διατεταγμένο οριζόντια. Όταν δεν εφαρμόζεται τάση, ο υγρός κρύσταλλος βρίσκεται σε φυσική κατάσταση και το φως που εκπέμπεται από το διάγραμμα αρχής λειτουργίας της στριμμένης νηματικής οθόνης TFT στο Σχήμα 2α μετά τη διέλευση από το ενδιάμεσο στρώμα θα συστραφεί κατά 90 μοίρες, έτσι ώστε να μπορεί να περάσει μέσω του κάτω στρώματος ομαλά.
When a voltage is applied between the two layers, an electric field is generated. At this time, the liquid crystals are aligned vertically, so the light will not be twisted-the result is that the light cannot pass through the lower layer.
TF:
Color filters are divided into three types: red, green and blue according to their colors. They are arranged on the glass substrate to form a group (dot pitch) corresponding to a pixel. Each monochromatic filter is called a sub{{0}}pixel (sub-pixel). ). In other words, if a TFT display supports a maximum resolution of 12801024, then at least 128031024 sub-pixels and transistors are required. For a 15-inch TFT display (1024768), then a pixel is about 0.0188 inches (equivalent to 0.30mm), for an 18.1-inch TFT display (12801024), it is 0.011 inches (equivalent to 0.28mm) As we all know, pixels are decisive for the display. The smaller each pixel is, the maximum resolution that the display can achieve will be
Μεγαλύτερος. Ωστόσο, λόγω του περιορισμού των φυσικών χαρακτηριστικών των τρανζίστορ, το τρέχον μέγεθος κάθε pixel του TFT είναι βασικά {{0}},0117 ίντσες (0,297 χιλιοστά), επομένως για μια οθόνη 15 ιντσών, το μέγιστο Η ανάλυση είναι μόνο 12801024.
1. Οθόνη GF LCD
GF is the abbreviation of "Glass Fine Color". Perhaps everyone is unfamiliar with GF LCD screens, because there are very few digital products using GF LCD screens on the market. In fact, GF is a kind of STN. The main feature of GF is that it guarantees power consumption. The brightness has been improved under the premise of smaller size, but the GF LCD screen has some color cast.
2. Οθόνη STN LCD
STN is the abbreviation of "Super Teisted Nematic", which belongs to passive passive matrix LCD. Almost all the LCD screens of black and white mobile phones are made of this material. The color STN LCD screen is to add a color filter on the basis of the monochrome STN LCD screen, and divide each pixel in the monochrome display matrix into three sub-pixels, and display red, green, and blue through the color filter. A variety of colors, so as to achieve a color picture. Due to technical limitations, the current STN LCD screen has a maximum of 65536 colors, and most of the STN products seen on the market are 4096-color STN products, so STN is also called "pseudo-color".
3. Οθόνη TFT LCD
TFT is the abbreviation of "Thin Film Transistor", also known as "true color". It belongs to the active matrix liquid crystal screen. It is a screen composed of thin film transistors. Each of its liquid crystal pixels is driven by thin film transistors. Behind each pixel, there are four independent thin film transistors to drive the pixel to emit colored light, which can display true color with 24bit color depth. In terms of resolution, the TFT LCD screen can reach up to UXGA (16001200).
The arrangement of TFT is memorable, so it will not return to its original state immediately after the current disappears, thereby improving the shortcomings of STN LCD screen flicker and blur, effectively improving the effect of LCD screen displaying dynamic pictures, and the ability to display static pictures More prominently, the dragon point of TFT LCD screen is that the response time is short and the color is bright, so it is widely used in notebook computers, DV and DC. The disadvantage of TFT LCD is that it consumes more power and costs more.
4. Οθόνη OLED LCD
OLED is the abbreviation of "Organic Light Emitting Display", also known as organic light-emitting display. It uses organic light-emitting technology, which is the latest display technology. OLED display technology is different from traditional liquid crystal display methods. It does not require a backlight. Instead, very thin organic material coatings and glass substrates are used. These organic materials will emit light when there is current passing through, so it has a large viewing angle, and the content on the screen can be seen clearly from all directions, and it can be done. It is very thin, and the OLED display can significantly save power, and is known as the "dream display."
But OLED is not without its shortcomings. Because it is still an immature technology, its service life is relatively short at this stage, and the screen area is relatively small.
Τα κύρια χαρακτηριστικά της οθόνης TFT LCD:
5. Οθόνη TFD LCD
TFD is the abbreviation of "Thin Film Diode". Due to the high power consumption and high cost of TFT LCD screens, which greatly increase the cost of the product, EPSON has developed TFD technology specifically for mobile phone screens, which is also active Matrix LCD screen, each pixel on the LCD is equipped with a separate diode, each pixel can be individually controlled, so that each pixel will not affect each other, which can significantly improve the resolution, and there is no smearing Display dynamic pictures and brilliant colors.
In terms of performance, TFD LCD screens take into account the advantages of TFT LCD screens and STN LCD screens. TFD LCD screens have higher brightness than STN LCD screens, and the colors are more vivid. At the same time, it is more power-efficient than TFT LCD screens. The brightness is still inferior to TFT LCD.
With the maturity of TFT technology in the early 1990s, color LCD flat-panel displays developed rapidly. In less than 10 years, TFT-LCD has rapidly grown into a mainstream display, which is inseparable from its advantages. The main features are:
(1) Καλά χαρακτηριστικά χρήσης: εφαρμογή χαμηλής τάσης, χαμηλή τάση οδήγησης και βελτιωμένη ασφάλεια και αξιοπιστία στερεάς χρήσης. επίπεδο πάνελ, ελαφρύ και λεπτό, εξοικονομώντας πολλές πρώτες ύλες και χρήση χώρου. χαμηλή κατανάλωση ενέργειας, η κατανάλωσή του είναι περίπου οθόνη CRT Το ένα-δέκατο αυτής, η ανακλαστική TFT-LCD είναι ακόμη και μόνο περίπου το ένα-εκατοστό του CRT, εξοικονομώντας πολλή ενέργεια ; Τα προϊόντα TFT-LCD έχουν επίσης προδιαγραφές, μοντέλα και μεγέθη σε σειρά, με διάφορες ποικιλίες, βολική και ευέλικτη χρήση, συντήρηση και ενημέρωση, εύκολη αναβάθμιση, μεγάλη διάρκεια ζωής και πολλές άλλες δυνατότητες. Το εύρος της οθόνης καλύπτει το εύρος εφαρμογής όλων των οθονών από 1 ίντσα έως 40 ίντσες και το μεγάλο επίπεδο προβολής. Είναι ένα τερματικό προβολής πλήρους μεγέθους-. η ποιότητα της οθόνης κυμαίνεται από τα πιο απλά μονόχρωμα γραφικά χαρακτήρων έως την υψηλή ανάλυση και την υψηλή πιστότητα χρωμάτων. Οθόνες βίντεο διαφόρων προδιαγραφών και μοντέλων με υψηλή φωτεινότητα, υψηλή αντίθεση και υψηλή ταχύτητα απόκρισης. Οι μέθοδοι προβολής περιλαμβάνουν άμεση προβολή, προβολή, προβολή-και ανακλαστική.
(2) Ο βαθμός αυτοματοποίησης της τεχνολογίας κατασκευής είναι υψηλός και τα χαρακτηριστικά της μεγάλης{{1}κλίμακας βιομηχανικής παραγωγής είναι καλά. Η τεχνολογία της βιομηχανίας TFT-LCD είναι ώριμη και το ποσοστό απόδοσης μαζικής παραγωγής έχει φτάσει πάνω από το 90 τοις εκατό .
(3) Το εύρος εφαρμογής είναι μεγάλο και μπορεί να χρησιμοποιηθεί κανονικά στο εύρος θερμοκρασίας από -20 βαθμούς έως συν 50 βαθμούς . Η θερμοκρασία λειτουργίας χαμηλής θερμοκρασίας του TFT-LCD μετά την επεξεργασία ενίσχυσης θερμοκρασίας μπορεί να φτάσει τους μείον 80 βαθμούς. Μπορεί να χρησιμοποιηθεί ως οθόνη τερματικού κινητού, οθόνη τερματικού επιτραπέζιου υπολογιστή και τηλεόραση προβολής μεγάλης-οθόνης. Είναι ένα τερματικό προβολής βίντεο πλήρους μεγέθους με εξαιρετική απόδοση.
(4) Good environmental protection characteristics: no radiation, no flicker, no harm to the user's health. In particular, the emergence of TFT-LCD e-books will bring mankind into the era of paperless office and paperless printing, triggering a revolution in human learning, dissemination, and recording of civilization.
(5) Το TFT-LCD ενσωματώνεται και αναβαθμίζεται εύκολα. Είναι ένας τέλειος συνδυασμός-μεγάλης κλίμακας τεχνολογίας ολοκληρωμένων κυκλωμάτων ημιαγωγών και τεχνολογίας φωτεινής πηγής και έχει μεγάλες δυνατότητες για συνεχή ανάπτυξη. Προς το παρόν, υπάρχουν άμορφες, πολυκρυσταλλικές και μονοκρυσταλλικές TFT-LCD πυριτίου. Στο μέλλον, θα υπάρχουν TFT άλλων υλικών, συμπεριλαμβανομένων των γυάλινων υποστρωμάτων και των πλαστικών υποστρωμάτων.
The TFT liquid crystal display is characterized by good brightness, high contrast, strong sense of layering, and bright colors, but it also has the disadvantages of relatively power consumption and high cost. TFT LCD technology has accelerated the development of mobile phone color screens. Many of the new generation of color-screen mobile phones support 65536 color displays, and some even support 160,000 color displays. At this time, the advantages of TFT's high contrast and rich colors are very important.
