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You can use this if you have a type with an external input port on USB camera.

 

Below is the USB camera with our external input port.

With the standard Viewer software (i Control), images are temporarily saved in the internal memory of the camera with an external trigger. (Paused state)

<How to save paused video>

1. Make a program
Once you’ve assembled the program, you can save it in the specified folder.
SDK (development support tool) is included in the attached CD.
Using this, we will form a program.
The following languages in red frame are available.

 

２．Use optional trigger software

By using our company software, you can save the image with an external trigger.

If you save for a certain time, you can easily create an external trigger by using a timer switch.

If you have any questions about trigger software, please contact technical support.

Customers may request “I want to save images using external trigger even with cameras without external trigger terminals”.
In this case, how about using existing input boxes?

Several Shortcut keys are set in the Viewer software Meats of Songpanyu.
For example, “Save” is set to “Ctrl + S”.

 

Using an existing input box, you can convert a signal (external trigger) from an external switch into a key signal such as “Ctrl + S”. In other words, instead of pressing “Ctrl + S” on the keyboard, you can save the image being displayed with the Viewer software Measure by turning on the external switch.

In this time I tried using “Anything Switch USB” (made by Techno Tools) to replace input box.

 

 

The setting methos as follow:

1. Connect an external switch to the terminal of the input box

2. Connect this input box to the PC via USB

3. Install software attached of input box on your computer

 

 

4. With the included software, It is mean to the external switch connected from 1 to 5 cable

For example, if you set “Ctrl + S” above as the output when the switch is on, you can save the image at an arbitrary timing using an external trigger.
Setup is completed.

Afterward, while displaying the image with Viewer software Measure, if you turn on the external switch at an arbitrary timing, you can easily capture the image even if there is no external trigger terminal on the camera.
Since it can be set easily, I think that it is worth having trial.

The PC’s C-State may be active, and this can be the underlying cause of the symptoms.

 

C-State, in simple terms, refers to a feature that puts the CPU in a low-power state to conserve energy in a PC.

Consequently, there are often instances where there is insufficient power supply from the USB, resulting in phenomena such as delayed or stuttering video when using devices like USB cameras. Particularly in Windows 10, C-State is enabled to extend battery life and promote power efficiency. It is distinct from the power plan’s power-saving mode.

 

If changing the power plan from power-saving or balanced to high performance does not resolve the issue, it may be necessary to disable C-State. Disabling C-State can be done through the BIOS, but the specific instructions may vary depending on the manufacturer, so it is not possible to provide a universal procedure.

 

If it is necessary to disable C-State, please contact our company for further assistance.

One of the causes may be is PC’s current supply is insufficient.

(It is not interfere, so we can not deal with repeater cable)

Especially notebook PCs may have a small power or in power saving mode in the initial state.

In this case, using a self-powered HUB (HUB with an AC adapter) is an easy solution.

The power supplied to the camera and active cable is now supplied from the HUB not the PC.

 

There is also a self power HUB with an ammeter as below

The following error occurs if the computer can not recognize the camera.

 

The 3 main causes are as follows:

1. The camera is not connected to the PC
2. The driver software of the camera is not installed
3. A driver of another camera is selected

<Solution>

Select Option -> Select Device.

 

Open Select Device.

Please select the connected camera from among these.

 

(In case there is no camera connected in the window)
It is possible that the driver is not installed.
→ Please install driver software.
You can download the driver software from here (Shodensha website).

Unfortunately there is sometimes cases like this. Even with USB devices, freezing may occur due to compatibility problems or interference. There are three problems as follow:

1. Communication failure

 

USB cameras do not have a retransmission function. The screen freezes when the communication is interrupted even once (communication error occurs).

The cause may be poor contact of USB connector, extension of USB cable, superimposition of noise, etc.

 

2. Interference with other driver software

 

Unlike application software, driver software is close to the system and may interfere with driver software such as Web camera. Not limited to cameras, video-based drivers and the like may interfere.

(In the past, there was also a case where the TV tuner board interfered.)

 

3. USB port problem

 

 If you are using a USB hub or an additional board USB port, the operation may become unstable.

<Solution> Of course, a problem of the camera body is also considered. To solve it, first run it on another PC to see if the same symptoms appear.

(It turns out whether the camera is a hardware malfunction or not.)

If there is no problem with other PC, connect to the PC where the error occurs, completely remove the driver, reinstall it. (

Unlike application software, driver software can not be completely deleted manually.

Please download “complete removal program” from our HP and use it. ) Be sure to check the operation using the port when reinstalling.

Our company possesses software with a timestamp feature, commonly known as a time-stamping function, capable of imprinting the date and time onto still images.

 

By utilizing the following trigger software, you can display timestamps down to the second and have them embedded within the still images when saving them.

 

 

 

Hi TriggerF Pro software :

 

https://www.shodensha.com.vn/vi/hi-triggerf-pro/ 

 

Hi TriggerF PRO4: 

 

https://www.shodensha.com.vn/vi/hi-triggerf-pro4/ 

Since our camera does not support the tablet exclusive OS (WindowsRT), please check OS first.
Please alsp note that it is not compatible with Mac.

■ General purpose type

	Lenovo　ThinkPad OS：Windows８Pro（32bit）  CPU：Intel　Atom　Z2760 strage capacity：2GB
	USB cable： port A

Display delay is severe, it is not a practical level.
The display delay seems to be a problem of the CPU’s calculation speed, memory, bit number.

Generally, it is said that “To run Windows 8, 64 bit, 4 GB are very nesscessary “
In the case of tablet general-purpose aircraft, there seems to be some lack of performance.

■High function machine type

	SurfacePro OS：Windows8Pro（64bit）  CPU：Intel　Core i5 starage capacity：4GB
	USB cable：　port A

The image is displayed normally. It is a level without problem in actual use of display speed.
I installed a 300M camera but it is a level without problems in actual use.

When using tablet, confirmation is necessary because the display speed may become very slow.
In addition, we recommend the type “Windows 8” “64bit” “Main storage capacity 4GB or more” “USB port is port Aand “Can be connected directly to camera” type.

API is an interface that is set up so that it can be programmed concisely to save programming time when programing an application called Application Programming Interface (Application Programming Interface).

SDK is software development kit (Software Development Kit).

Currently, we have a model that exposes the SDK and a model that has not released the SDK.
Since our USB camera supports Directshow, it is possible to make camera application program using DirectX SDK provided by Microsoft Corporation.

 

“32 bit” and “64 bit” are the way of a computer’s processor (also called CPU) processes information. The 64-bit version of Windows can process large capacity random access memory (RAM) more efficiently than 32 bit system.

In Windows XP, Vista, except for special ones, it was 32 bit. Therefore, the camera was only 32 bit compatible.
However, 32 bit and 64 bit is quite popular for Windows 7. Even if a 64bit signal is sent to a camera whose element itself corresponds only to 32bit, it does not move. It can not cope with software update. It is necessary to change the element itself to 64 bit.
USB microscope and USB camera which we currently sell are all 64bit compatible.

 

 

The continuous connection of still images taken at intervals is referred to as a time-lapse video. It is also known as slow-motion filming.

In contrast to slow-motion videos captured with a high-speed camera, which display footage in slow motion, time-lapse videos compress long-duration recordings into shorter playback times.

Consequently, unlike prolonged video recording, time-lapse videos require less storage capacity while enabling extended periods of capture.

Furthermore, since each frame is a still image, high-resolution filming is also achievable.

 

＜Reference＞ Below is a sample video of time-lapse found on YouTube.

https://www.youtube.com/watch?v=UQ_QqtXoyQw 

 

(It can be applied to capturing the slow changes of various subjects, such as microbial movement and tissue culture.)

 

Capturing time-lapse videos can be easily done even without dedicated equipment.

Method for Time-Lapse Shooting:

(1) Many cameras come with built-in time-lapse shooting features, which allow for easy capturing.

(2) You can also download time-lapse compatible apps and use your smartphone for shooting.

(3) Perform interval shooting to capture still images. Then, utilize editing software to create a time-lapse video.

 

Create a time-lapse video using our company’s product

 

To create a time-lapse video using our company’s product, you can follow the method mentioned in (3) above.

To perform interval shooting with our USB camera, you will need to use our dedicated software, Hi TriggerQ, to capture the subject and save multiple still images.

 

 

 

＜Introducing Hi TriggerQ＞ ■Interval Shooting Capability You can set any desired time interval for interval shooting. (From 1 second to 99999 seconds) It allows convenient capture of still images, which is useful for creating time-lapse videos.   With our company’s USB camera, time-lapse shooting is possible for various applications, such as macro photography using a microscope, and monitoring purposes using regular fixed-focus lenses for line surveillance.

 

Firstly, we attempted interval shooting within our company premises using the aforementioned software.

 

 

 

 

We then used editing software to merge and create a video from the captured images.

There are various editing software options available, such as Windows Live Movie Maker. However, for this particular case, we tried using the free software called “Panolapse.”

 

 

 

 

Due to limitations in the free version, we reduced the resolution of the still images.

(These limitations can be lifted by purchasing a license.)

The downloaded files will be in the following format:

 

 

 

 

When launching Panolapse.exe, the following screen will appear:

 

 

 

 

Please follow these steps to import all the still images captured during the interval shooting into Panolapse:

 

 

By following these steps and clicking the preview button, your time-lapse video will be created.

 

Note:

Please note that the editing software mentioned (Panolapse) is not our company’s product. This is just one example provided for reference purposes.

 

 

 

White balance is correction in order to obtain an image of normal color tone under light source of various colors in the camera.

There are many different adjustment methods. But our products just apply the auto white balance with one button.

 

There are various adjustment methods. In our case we adopt one push auto white balance. We will adjust the brightness so that you can observe the color reference (I think that using the blank paper is the best) in a state without halation (whitening) or too dark.

After that, color correction (auto white balance) is automatically applied when you click the white balance key once.

The notation differs depending on the camera such as: AWB, OnePushWB.

 

 

 

Our software MeasurePro, MeasurePRO – Ex, can not be measured radius.
Software can measure radius is also sold by other companies.
Since our USB camera is compatible with Directshow, various software can be used as well as our software sold

1. Using lens with aperture
(LRS series, MS series, SG series, CCTV lens, etc.)

If you use a diaphragm with a diaphragm function, the depth of focus will be deeper. However, the resolution will be lower.
If there is no problem of depth of focus, we recommend opening the aperture as much as possible.

2. Reduce the influence of R and C on the edge of the object.
If there is C face or R face on the edge of the observation object, it may be blurred due to the depth of focus problem.
(For details, please refer to “How to look at the edges of the R side cleanly.”)

There is also a method called binarization when observing only edges in dimension measurement applications and so on.
There are the following two methods for binarizing.

(1) Use transillumination to make a silhouette screen.
(2) Use software binary mode.

If the number of pixels in a camera is high, the resolution will be high. It is very hard to rough the image even if it is enlarged on a personal computer. However, since the data capacity becomes heavy, the data transfer speed to the personal computer will be slow. In other words, screen display in real time tends to be delayed against movement such as focusing and positioning.
PC monitor also has resolution, if it is only for observing on the PC screen and saving the image, there is not much difference in any pixel number, about 2 million pixels is sufficient.
If there are many uses such as applying digital zoom to the saved image, the number of pixels will be dominant.

	1.3 mega pixel	2.0 mega pixel	3.0 mega pixel	5.0 mega pixel
frame rate	slow			fast
resolution	low			high
price	low			high

However, since you can switch the resolution to each camera, please save it at full resolution when observing and saving at low resolution.

<Frame rate and frame switching of each USB 2.0 camera>

model number	GR300BCM2	GR500BCM2
max resolution	2048×1536	2592Ｘ1944
frame rate	6frame/sec　 （2048×1536）	4frame/sec　 （2952×1944）
Resolution switching	2048×1536 1024×768 640×480	2592×1944 1280×960 1024×768

 

We will select the suitable camera depend on your requirements. Please feel free to contact our Technical Advisor.

Adjust the display speed (frame rate) of camera which used with our 3.0 USB microscope by time.

The upper limit is decided and this value takes precedence.
(Even if you change FrameSpeed or the resolution, it does not exceed this limitation)
However, if the processing speed of the camera can not catch up, it will be subtracted from the setting of upper limit value.

■ If there is enough processing speed, the display speed (frame rate) will not change even if the resolution is changed.
<Set resolution to 640 X 480>

< Set resolution to 2532 x 1944>

■If there is enough processing speed, the display speed (frame rate) will not change even if the resolution is changed.

<Set resolution to 640 X 480>

Frame speed is at Super.

Frame speed is at high

Frame speed is at normal

■You can rise the upper limitation by adjusting TIME

If the processing speed is not enough, the frame rate will be decline by adjusting the resolution and Frame Speed with the upper limitation which is set at Time.

<Adjust fixed Frame Speed to 640 X 480>
Frame Speed is at super

Frame Speed is at high

Frame Speed is at normal

Our USB camera is Directshow compatible, we can divert a lot of image processing software.
It can be used if it is Viewer software for Directshow.

In case you do not know whether your camera is compatible with Directshow or not, please check the operation with AMCap distributed free charge by Microsoft Corporation. If it seems to work, it is Directshow compatible camera.
If the camera is supported by Directshow, it is possible that we can use population Viewer software as well as Viewer software released by our company.

With Measure, Viewer software which is standard equipment of USB Microscope, it is possible to shoot every second.

 

 

You can set up how many seconds to shoot on Interval.

 

I just try to use this function to shot the second hand of the watch every second.

I was able to capture the movement of the second hand.

Click this button in the toolbar, the interval setting screen will show up.

 

In addition, our USB microscope uses Directshow compatible USB camera, so software is extensible and it can run with other software.

Besides that, if you would like to know the details of the software, please contact the Technical Support Dept.

。

Including free-to-charge.  There are many types of interval shots available

 

The application software 「Measure」 is standard equipment of our USB camera. However, the limit of Interval is with a minimum of 100 seconds, the maximum number of shots is 999.

 

We also offer optional software that allows for shooting with longer intervals and without any limitations on the number of shots.

 

SOFTWARE FOR 4 SCREENS DISPLAYS　Hi TriggerQ

For me, it will be very convenient for shooting time lapse photography of microscopic activities (bacterial culture, tissue culture, microbial culture, etc.). (Please refer to What’s video time lapse?)

From customers, we sometimes receive requests such as, “I would like to capture and save long-duration videos using a USB camera.”

In this instance, we would like to present several methods for capturing long-duration videos using a USB camera.

 

Utilizing the multifunctional compressed video recording software known as “Hi TriggerREC.”

 

Our company provides the software called “Hi TriggerREC” for use with our USB 3.0 camera, enabling effortless creation of long-duration videos.

 Notable features of “Hi TriggerREC”:

– Possibility to record videos in H.264 compression (.mp4) or uncompressed (.avi) formats.
– A diverse range of additional functionalities, including a snapshot feature for capturing still images at any time and a variety of recording/stop triggers combining external signals and timers, is also included.

You can use the included viewer software that comes standard with the USB camera.

 

With our USB 2.0 camera, you can record using the provided standard viewer software. However, please note that the AVI file format it exports is outdated and has a file size limitation of 2 gigabytes.

 

If you require a shorter recording time, you can use this viewer software. For example, with the 1.3-megapixel type (1280×1024) at 30 frames per second, you can record for approximately 15 seconds.

 

 

 

You can utilize commercially available or free recording software for your USB 2.0 camera.

 

As our USB 2.0 camera can also be used as a DirectShow camera, you can generally record using commercially available or free recording software that supports DirectShow. If you have such recording software, you can verify its compatibility by utilizing our demo unit for recording testing.

 

One well-known free option is the software called “Amcap” provided by Microsoft as a sample program. Please note that it only supports the uncompressed format (AVI) for saving recordings. 

 

 

 

 

You can achieve long-duration recording on a computer using a conversion device

 

While it is not specific to USB cameras, one method is to attach a USB 3.0 converter to a high-definition camera and perform long-duration recording on a PC.

 

By using the GV-USB3/HD device from I-O DATA, you can capture videos with all models of our high-definition cameras.

 

1. Changing the resolution as high as possible.

There is resolution switching in application software.

(However, the resolution is higher, display speed is lower)

2. Adjust video properties.

The format of the setting screen depending on the camera. But, the setting items are roughly the same.

At high, the image quality is reduced

When you check AE, If the outside light is dark, the

image quality decreases

 

If Gain increases, the noise component will be amplified. So, the image quality will decrease.

 

If you increase the brightness too much on software, the noise component will also increase.

Basically, it is recommended to set the external lighting to sufficient brightness, uncheck the AE (auto white balance) and reduce gain as much as possible.

Flicker is a phenomenon that occurs in a screen in which the screen flickers, lines appear on the screen or repeatedly light and dark.

Prevention methods are as follows:

1. Change the frequency in Property to be able to synchronize with the power frequency and fluorescent lamp.

2. If there is noise from a fluorescent lamp or power supply, please talk to the customer to remove it.

3. If automatic exposure is applied, try removing AE (Auto Exposure).

By using our software MeasurePro, MeasurePRO – Ex, you can showcross lines.

 

For MeasurePRO and MeasurePRO – Ex, it is possible to show cross lines at optional positions

If you have any questions, please feel free to contact our Technical Advisor.

The upper limit of USB communication speed is decided regardless of PC performance.

For USB 2.0, it is 480 Mbps (= 60 MB / s).

It can not exceed this. (Actually, 60% of this number does not come out.)

Of course, there are also ways to stop the resident software (skype, security software, etc.) and increase the installed memory, etc., which increases the ability of the CPU on the PC side.

 

You can also raise the frame rate with the setting on the camera.

・Increase shutter speed

Please check the setting screen on the camera. There are items to adjust the shutter speed. (Depending on camera of each company, time,   exposure time, etc, the function will change.)

Please set this as soon as possible. (In that case the screen will be dark, please make the lights as bright as possible.)

<Pls look at the setting screen of our viewer software>

・Stop feedback

Depending on the camera, automatic exposure (AE) and real-time white balance may be set.

Turning this off and setting it to manual setting, feedback time can be shorten.

<Please look at the setting screen of our viewer software>

・Decline the resolution

If it is a CMOS camera, the resolution can be switched. The resolution will be lower if full resolution is not required.

・Change CMOS camera to CCD camera

This is not actually going to be faster. When you compare with the same resolution, the speed will be increased. (Actual easier to see.)

(Please refer to “What’s the difference between CCD and CMOS?”.)

・Video format also affects to the speed

For YUY 2, RGB 24, the camera will send the data to the PC.

On the other hand, video formats such as RAW 8 and RAW 16 send data directly to the PC and build the video on the PC side.

Although a burden is imposed on the PC side, if there is sufficient ability on the PC side, the display speed of the picture increases.

 

Of course, changing from USB 2.0 to USB 3.0 will make it overwhelmingly faster.

Recently, in addition to just USB 3.0, there is also a camera of the “USB 3 Vision” standard, not only the display speed but also the stability is greatly up.

(Please refer to “What is USB3Vision”.)

 

The concept of “shutter” does not exist in industrial cameras as it does in consumer cameras. Instead, industrial cameras employ the idea of controlling “exposure time” and “frame rate” separately, rather than simply “taking a shutter shot.” The exposure time in industrial cameras is similar to the shutter speed of consumer cameras.

In the case of industrial cameras, the difference in exposure methods results in two categories: rolling shutter and global shutter.

Please consider this as a distinction based on the difference in exposure methods rather than a physical shutter.

 

The difference between rolling shutter and global shutter

 

＜Rolling shutter＞

 

Rolling shutter is also called “line exposure sequential readout”.

Collect one block from one line to one block and obtain the image for each block.

Combine this into one image. Although the inside of the block is simultaneous timing, a slight time difference occurs for each block.

CMOS cameras are generally rolling shutters.

(CMOS devices can read all pixels or read out partial images. Recently, cameras that can switch between rolling shutter and global shutter are also on sale.)

＜Global shutter＞

 

Global shutter is also called “simultaneous exposure all at once”.

Images are acquired at the simultaneous timing of all pixels.

CCD cameras are generally global shutters.

(Because the CCD element can not read out partly, it is inevitably a global shutter.)

 

Differentiating between rolling shutter and global shutter usage

 

I think that the following two points are important for practical use.

(1) When photographing a moving object

(2) When using strobe lighting

 

(1) When photographing a moving object

 

 

Try shooting while moving the following objects.
Global shutter（CCD）	Rolling shutter（CMOS）
Since the shooting time of the rolling shutter is shifted from block to block, the image skews. In addition, CMOS also generates a large afterimage. Try shooting while moving the following objects.
Global shutter（CCD）	Rolling shutter（CMOS）

 

When capturing moving subjects, global shutter is more suitable.

(2) When using strobe lighting

If you use a camera with a rolling shutter for flash photography, there may be instances where only a part of the screen lights up or certain areas are not captured.

 

 

Let’s try capturing the subject in the photo below using a camera with a rolling shutter for flash photography.

 

 

 

		The phenomenon of certain parts not being captured.
		The phenomenon of only a specific portion being illuminated.

 

When it comes to flash photography, global shutter is more suitable.

Considering the two points mentioned above, global shutter seems to be the better choice. However, rolling shutter also has its advantages.

The benefits of rolling shutter are as follows:
– Lower manufacturing cost
– Easier implementation of high resolution

 

■ Our Camera Lineup

– All of our high-resolution cameras with 10 million pixels or more are equipped with a rolling shutter.

– Our USB cameras come in 400,000 pixels, 1.3 million pixels, and 2 million pixels, all featuring a global shutter.

– We also offer global shutter models with 3.2 million pixels and 5 million pixels, but they are exclusively available in the GigE interface and come at a significantly higher price.

Allow us to introduce some of our cameras, including the global shutter models. (Please note that we have a wide range of other camera options available as well.)

<Global Shutter Camera Models>

 

Name	Color and Monochrome	Pixel count	Shutter type	FPS	Interface	Price (excluding tax)
CS41-C	Color	400,000 pixels	Global	120fps	USB3.0	69,000 JPY
CS41-B	Monochrome	400,000 pixels	Global	120fps	USB3.0	69,000JPY
CS500U-GC	Color	5MP	Global	59.8fps	USB3.0	110,000JPY
EG320-C	Color	3.2 million pixels	Global	37.5fps	GigE	115,000JPY
EG320-B	Monochrome	3.2 million pixels	Global	37.5fps	GigE	115,000JPY
EG501-C	Color	5MP	Global	24.1fps	GigE	157,000JPY
EG500-B	Monochrome	5MP	Global	23.5fps	GigE	157,000JPY

 

<Rolling Shutter Camera Models>

 

 

Name	Color and Monochrome	Pixel count	Shutter type	FPS	Interface	Price (excluding tax)
CS500-C	Color	5MP	Rolling	44.7fps	USB3.0	71,000JPY
CS500-B	Monochrome	5MP	Rolling	31fps	USB3.0	71,000JPY
CS1200-C	Color	12MP	Rolling	30fps	USB3.0	99,000JPY
CS1200-B	Monochrome	12MP	Rolling	30fps	USB3.0	99,000JPY
CS2000-C	Color	20MP	Rolling	14fps	USB3.0	110,000JPY
CS2000-B	Monochrome	20MP	Rolling	14fps	USB3.0	110,000JPY

 

 

We have compiled a video summarizing the differences between rolling shutter and global shutter in our company. Please refer to the video for more information. 

 

 

 

Summary: 

In industrial cameras, rolling shutter and global shutter refer to the difference in exposure methods rather than physical shutters.
Rolling shutter, known as “line exposure sequential readout,” is commonly found in CMOS cameras.
Global shutter, known as “simultaneous exposure simultaneous readout,” is commonly found in CCD cameras.

(1) When capturing moving subjects and (2) when performing flash photography, global shutter is more suitable.

 

Windows Embedded is a generic term for operating systems families with objects that are installed by Microsoft devices.

For OS system, it changes depending on which driver / function is installed in the OS can not be used or not.

Based on the information mentioned above, I think there are few USB cameras officially stating that Windows Embedded is compatible.

However, if your embedded Embedded OS has a driver that recognizes the imaging device, you can use the USB camera just like a normal OS.

 

In fact, some customers are using our  DN 3 series.

 

USB3.0 camera DN3 series

 

Have you ever felt that the screen display is very slow when using a USB camera?

 

For example, “Screen does not change for several seconds”, “Freeze well”, and so on.

Actually, the PC’s ability is very high, even if the empty memory capacity is sufficient there is a possibility of occurrence.

 

The reanson is compatibility between PC and camera.

“Compatibility” is abstract, so I will explain it.

 

USB camera consists of a sensor section and a buffer (memory section).

Sensor sends video data to memory at pixel clock (frequency).

Video data is saved in the data memory by overwriting.

(Memory is very large, some types are not all overwritten.)

 

On the other hand, USB host controller will receive the signal.

(You can check with PC’s device manager.)

There is a so-called Polling Rate or Frequency of Receiving Data

 

Drop in pixel clock and polling rate unmatching. Therefore, when the image increases, it gets slow. In this case, the image display may be delayed extremely.

 

Some USB cameras can also change the pixel clock. In addition, the number of missed frames may be displayed.

 

You can maximize the performance of your PC and USB camera by adjusting the pixel clock while confirming the number of missed frames.

(Of course, the frequency and the display speed are higher if no images are lost)

 

We also sell USB cameras that can adjust the pixel clock.

Please refer here.

 

USB 2.0 standard cable is up to 5 m.

In fact, cables excessed this standard are sold by major manufacturers.

(It is said that there is not much effect on the communication speed up to about 10 m.)

Not only the standard extension cable but also other types as below are also sold

It is “USB cable with repeater function”.

Although there are a lot of companies sells it, the product shows in below photo is KB-USB-R212 from Sanwa Supply Co., Ltd【12m USB extension repeater cable】

According to the standard of USB cable, the length of the cable is determined to be the longest 5 m between the devices.

However, by using “USB cable with repeater function”, you can connect devices with 5 m or more cable.

In below photo, this cable can be extended by 12 meters.

 

This cable has a built-in signal amplification correction circuit. By restoring the signal attenuated by this circuit, it is possible to extend the cable.

This cable can be extended by 12 m or more. In that case, wire as shown below.

I tried using 12 meters of repeater equipped USB cable (photo below) and camera attached cable (1.8 m) to our USB camera but it worked well without any problem. However, there is a sentence in the explanation of the USB cable with repeater function (product of the photograph) that “USB device to be connected recommends a device that operates with self power in order to perform stable operation”.

 

Voltage drop will occur when the USB cable is extended. So, it is recommended that you always check the operation on devices that operate by supplying power from the PC (including our USB camera).

 

By the way, USB 3.0 is supposed to be up to 3 m.

Since USB 3.0 standard does not allow cable relaying, it is safe to avoid relaying with extension cable within 3m.

I think that it is better to use a repeater cable or relay the HUB as described above.

However, we recommend a repeater cable and HUB with self power (with AC adapter).

 

Recently, there is also an active cable.

IC for signal conditioning is built in the connector part and extension is made possible without preparing another power supply.

 

The frame rate is the number of frames to be processed per unit time in video. It is usually expressed as a number per second and uses the unit of fps (frame / sec).

 

For USB, the upper limit (the maximum value on the theoretical value) is determined regarding to PC function.

USB 2.0 is 480 Mbps (= 60 MB / s)

USB 3.0 is 5120 Mbps (= 640 MB / s)

 

 

If it is a USB camera with USB 2.0, theoretically

If color data of 1.3 million pixels (1280 X 1024), it is about 15 fps

If it is color data of 2 million pixels (1600 X 1200), it is about 10 fps

If color data of 3 million pixels (2048 X 1535), it is about 6 fps

. (It will not change significantly with camera performance or price.)

 

However, It is a theoretical value, it varies greatly depending on the capabilities of the CPU, memory and other environments (eg: regular software).

Actual measurement seems to be mostly about 60% or less of the theoretical value.

Among them, there is also a way to raise the frame speed slightly.

(Refer to “How to Increase the Frame Speed”)

 

The mechanism of video is simply a “Flip Book”.

The one used for piece by piece of the “Flip Book” are “Images”.

 

For example, if you have a resolution of 1920 x 1080 (full Hi-vision) “30 frames / sec”, you need 1800 images in 1 minute.

If you make this as a video, it will become a huge file size of 15 GB in 3 minutes.

 

Therefore, it is common to use resolution of about 640 × 480 (300 thousand pixels) when saving with uncompressed file (extension AVI etc.).

(Nevertheless, it will be about 1 MB in 1 second.)

 

If you can not reduce the resolution, you will have to reduce the file size by compressing each image using the “compression algorithm” called “codec”.

Currently, “codecs” are common used as H.264, VP9.

The extension of video files with H.264 is compressed by MP4. The extension of video fileswith VP9 is compressed by webm.

 

By the way, licensing fee will be incurred as H.264 contains patents.

For that reason, there are hardly any things that can be saved as video with MP4 files with free software that has a video recording function.

(There seems to be many uncompressed AVIs.)