A TV's refresh rate is how many times the screen refreshes itself every second. It's different from frames per second fps , which defines how many frames the video source displays every second. The refresh rate is important for motion handling, as a higher refresh rate generally results in smoother motion, but it's not always the case.
It's also important to not get confused with marketing terms that often inflate the refresh rate. This article explains the differences between a 60Hz and Hz refresh rate, how it affects the image, and how companies will try to trick you into thinking the TV has a higher refresh rate than it actually has. Even though we don't see it, our TV is constantly refreshing itself every second. A refresh rate defines how many times per second it draws a new image on the screen, and it's written out in Hertz Hz.
A 60Hz refresh rate means that the screen is refreshing itself 60 times every second, and at Hz, it's refreshing itself times every second. This is different from frame rate, which is how many times per second the source sends a new frame. The refresh rate affects motion handling; the more times the display can draw a new image the better it is for fast-moving content. Modern TVs either have a 60Hz or Hz refresh rate. Most high-end TVs have a Hz refresh rate, but it doesn't mean they're inherently better at motion handling either.
The response time determines how good motion looks; a quick response time means that motion looks clear, while a TV with a slow response time leads to motion blur. Response time and refresh rate are indirectly related as a Hz panel is expected to have a better response time than a 60Hz panel, but it's not a guarantee. Since not all content will automatically have the same frame rate as your TV's refresh rate, there are also ways a TV increases the frame rate to match up with the refresh rate, improving the appearance of motion.
In a case like this, the TV either adjusts itself to match the refresh rate of the source, which effectively turns it into a 60Hz TV, or it simply doubles every frame. As you can see from the picture above, a TV with a higher refresh rate doesn't produce less motion blur. Since both of these TVs have a very similar response time, 60 fps content results in an almost identical picture.
To better showcase these differences, we compared two TVs side-by-side; a 60Hz model, and a Hz model, with similar response times. We filmed these TVs in slow motion to easily compare each individual frame.
One of the most important advantages is the ability to play back content that is meant to be displayed at 24 fps, which is often found in movies. Most TVs can simply lower their own refresh rate to 24Hz when the content is 24 fps, but some sources, such as Chromecast, output video at 60 fps, even if the content is 24 fps.
This means that the TV's refresh rate remains at 60Hz, and motion won't appear smooth, which is an effect called judder. A 60Hz TV has trouble removing 24 fps judder because 60 isn't a multiple of To display this type of content, a technique known as a " pulldown" is used. Basically, 12 of the 24 frames repeat three times, while the other 12 repeat twice, totaling 60 frames. Not everybody notices this, but it causes some scenes, notably panning shots, to appear juddery.
However, Hz TVs have an advantage here because they can simply display each frame five times since is a multiple of There are a few sources that display fps, such as the Xbox Series X or the PS5 , and having a Hz TV helps display this content at its max frame rate. While it's rare to find content other than games with this frame rate, displaying fps has a significant impact on the perceived motion. As you can see in the picture below, content looks much smoother at fps than at 60 fps on a Hz TV.
With the release of HDMI 2. This means that Hz TVs may slowly become the norm. Another place where Hz is useful is if you enjoy the motion interpolation feature found on TVs also known as the Soap Opera Effect. It allows the TV to generate frames between existing ones, increasing the frame rate to match up to the refresh rate.
This is why a Hz TV is an advantage over 60Hz since it can interpolate more types of content. There are other ways to produce a similarly clear image as a Hz refresh rate. Essentially, the TV displays a black screen between each frame, which most people can't see, but it can also make the screen dimmer.
On most LED TVs, this is achieved by adjusting the flicker frequency of the backlight, which results in the backlight being turned off for half the frame. This can be problematic for electric motors. This is especially true when operating pump and fan loads. Often, the distributors and purchasers of this machinery assume that the Original Equipment Manufacturer has taken this into consideration. This is recognized when motors are received for repair roasted out from overload.
Motor speed is directly proportional to the operating frequency. Changing the operating frequency on a pump or fan increases the operating speed, and consequently increases the load on the motor. A pump or fan load is a variable torque load. A variable torque load varies by the cube of the speed.
The load will become 1. Redesigning a motor for that much of a horsepower increase is not possible. One solution would be to modify the driven equipment to decrease the load. This may include trimming the diameter of the fan wheel or impeller to provide the same performance at 60 Hz as the unit had at 50 Hz. This will require consultation with the OEM. There are other considerations associated with an increase in speed besides the increase in load. These include mechanical limitation, vibration limits, heat dissipation, and losses.
The best solution is to operate the motor at the speed for which it was designed. If that is 50 Hz. These drives will convert the 60 Hz line power to 50 Hz at the motor terminals.
There are numerous other benefits that will be realized with this solution. These benefits include:. Source: Precision Electric, Inc. Email: sales ksbusa. Sub-Navigation Conquer The Clog. The result is a smoother display as the TV is better able to process faster movements. At the time of publication, however, the 60 Hz has been surpassed by faster refresh rates such as Hz, Hz and Hz.
Also, such faster rates are often paired up with video processing technology to reduce judder, which is a vibrating camera movement that occurs during conversion of film content to video. Some companies have their branded forms of these technologies, Sony Corp.
However, the 60 Hz refresh rate is efficient enough for curbing motion blur and judder. Although a faster rate is more effective, there is always the danger of smoothening or stabilizing pictures to the extent of rendering them with an unnatural feel.
This is due to excessive outpacing of source material.
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