JP7158782B1 - video signal converter - Google Patents

Abstract

A technique capable of adjusting the length of a horizontal line of an output video signal and preventing the adjustment from biasing only a specific horizontal line is provided.
A signal conditioning device (50) is applied to a video signal conversion device (10) for converting an input video signal into an output video signal. The output video signal is a video signal containing a predetermined number L2 of horizontal lines, which are signal groups separated by horizontal synchronizing signals. The adjustment unit 52 selects a plurality of adjustment lines from the predetermined number L2 of horizontal lines in each frame of the output video signal, adjusts the timing of the horizontal synchronization signal, and adjusts the length of each of the plurality of adjustment lines. Adjust the depth to a value greater or less than the reference value.
[Selection drawing] Fig. 1

Description

The present disclosure relates to a signal conditioning device and a video signal conversion device.

Patent Document 1 discloses a semiconductor device having an interface for digital video signals. The semiconductor device disclosed in Patent Document 1 includes a first receiver that receives serial data including a plurality of odd-numbered pixels positioned horizontally in one frame, and a receiver that receives serial data including a plurality of odd-numbered pixels positioned horizontally in one frame. and a second receiver for receiving serial data including a plurality of even pixels to be processed. Further, the semiconductor device includes a signal processing section that integrates the plurality of odd-numbered pixels and the plurality of even-numbered pixels to generate line data. Then, the signal processor scales the line data and distributes it to the transmitters corresponding to the normal source drivers.

WO2019/208390

A video signal to be supplied to a display device such as an in-vehicle monitor is generally one in which one frame is divided into a plurality of horizontal lines by a horizontal synchronizing signal, and the switching timing of one frame is determined by a vertical synchronizing signal. When using this type of video signal, it is assumed that the length of the horizontal line should be adjusted.

For example, when displaying a video signal output from an external device on an in-vehicle monitor, it may be necessary to scale the signal to a size suitable for the in-vehicle monitor. For example, if the image size of the input video signal supplied from the source device is 1600×900, and the number of clocks of the horizontal synchronizing signal is 2000 clocks and the number of lines is 1000 lines in one frame of the input video signal, 60 FPS. , the frequency of the clock signal is 120 MHz. On the other hand, when the image size of the output video signal to be output to the in-vehicle monitor is 800×450, and the number of clocks of the horizontal synchronizing signal is 1000 clocks and the number of lines is 500 lines in one frame of this output video signal. In order to generate one frame of the output video signal with the same period of 60 FPS as that of the input video signal, the frequency of the clock signal must be 30 MHz. By performing such scaling, it is possible to change the image size to be suitable for the display device while matching the frame period with the input video signal. Note that the period of one frame is the period from the output of one vertical synchronizing signal to the output of the next vertical synchronizing signal.

When performing such scaling, in the output video signal, the timing at which the final horizontal line should end (timing 1000 clocks after the output of the final horizontal synchronizing signal) and the frame switching timing (the next vertical synchronizing signal ), the clock frequency of the output video signal must be exactly 30 MHz. However, it is conceivable that for some reason the clock frequency of the output video signal cannot be set accurately to the desired frequency (for example, the frequency resolution of the device is low and the frequency deviates from the desired frequency). In such a case, there is a concern that the switching timing of one frame based on the vertical synchronizing signal will deviate from the timing at which the final horizontal line should end, resulting in a horizontal line having a length outside the allowable range. Note that the above problem is merely an example, and it may be desirable to adjust the length of the horizontal line of the output video signal in other situations as well.

In order to solve at least one of the above-described problems, the present disclosure provides a technique that can adjust the length of the horizontal line of the output video signal and can suppress bias in adjustment only to a specific horizontal line. offer.

One signal conditioning device of the present disclosure includes:
Outputs an output video signal containing a predetermined number of horizontal lines, which is a signal group for each line separated by a horizontal synchronizing signal and a signal group for each frame separated by a vertical synchronizing signal based on an input video signal to be input. A signal conditioning device applied to a video signal conversion device that
including an adjustment unit that adjusts the timing of the horizontal synchronization signal of the output video signal,
In the predetermined number of horizontal lines included in the output video signal, a plurality of data lines including pixel data continue, followed by a plurality of blank lines not including the pixel data. All or part of the length is the standard value,
The adjustment section selects a plurality of adjustment lines from the predetermined number of horizontal lines in each frame of the output video signal, and adjusts the timing of a horizontal synchronization signal to adjust the length of each of the plurality of adjustment lines. The height is adjusted to a value greater or less than the reference value.

The technique according to the present disclosure can adjust the length of the horizontal line of the output video signal, and can prevent the adjustment from biasing only a specific horizontal line.

FIG. 1 is a block diagram schematically showing an in-vehicle system including a signal conditioner of the first embodiment. FIG. 2 is a block diagram for explaining the specific configuration of a signal conversion section forming part of the video signal conversion device used in the vehicle-mounted system of FIG. FIG. 3 is an explanatory diagram for explaining the concept of scaling. FIG. 4 is an explanatory diagram conceptually explaining one frame of the intermediate video signal. FIG. 5 is an explanatory diagram conceptually explaining one line of the intermediate video signal. FIG. 6 is an explanatory diagram for explaining a horizontal line adjustment method. FIG. 7 is an explanatory diagram for explaining a problem when horizontal line adjustment is not performed. FIG. 8 is an explanatory diagram for explaining an example different from FIG. 6 regarding the horizontal line adjustment method. FIG. 9 is an explanatory diagram for explaining an example different from FIGS. 6 and 8 regarding the horizontal line adjustment method. 10A and 10B are explanatory diagrams for explaining an example different from FIGS. 6, 8, and 9 regarding the horizontal line adjustment method.

Embodiments of the present disclosure are listed and illustrated below. The features [1] to [6] exemplified below may be combined in any way within a consistent range.

[1] Based on the input video signal to be input, an output image including a predetermined number of horizontal lines, which is a signal group for each line in which a signal group for each frame is separated by a vertical synchronizing signal and which is separated by a horizontal synchronizing signal in each frame. A signal conditioning device applied to a video signal conversion device that outputs a signal,
including an adjustment unit that adjusts the timing of the horizontal synchronization signal of the output video signal,
In the predetermined number of horizontal lines included in the output video signal, a plurality of data lines including pixel data continue, followed by a plurality of blank lines not including the pixel data. All or part of the length is the standard value,
The adjustment section selects a plurality of adjustment lines from the predetermined number of horizontal lines in each frame of the output video signal, and adjusts the timing of a horizontal synchronization signal to adjust the length of each of the plurality of adjustment lines. A signal conditioner that adjusts the amplitude to a value greater or less than the reference value.

The signal adjustment device of [1] above can adjust the length of each of the plurality of adjustment lines to a value larger or smaller than the reference value by adjusting the timing of the horizontal synchronization signal. That is, the signal conditioner can adjust the length of each of the adjustment lines to a length different from the reference value. Moreover, since this signal adjustment device can perform adjustment by distributing it to a plurality of adjustment lines, it is possible to prevent the adjustment from being biased only to a specific horizontal line. Easier to troubleshoot issues that arise.

In this specification, the timing of the horizontal synchronizing signal means the output timing (each start timing) of each horizontal synchronizing signal that is periodically output. For example, "the timing of the horizontal synchronizing signal in each frame of the output video signal" is the output timing (each start timing) of each of the plurality of horizontal synchronizing signals included in each frame of the output video signal. The time length of one adjustment line is determined from the output timing (start timing) of the horizontal synchronization signal that determines the start time of the adjustment line to the output of the horizontal synchronization signal that determines the start time of the horizontal line next to the adjustment line. It is the length of time until the timing (start timing). Therefore, in order to adjust the temporal length of the adjustment line, the adjustment section determines the output timing of the horizontal synchronization signal that determines the start time of the adjustment line and the start time of the horizontal line next to the adjustment line. The output timing of the horizontal synchronizing signal may be adjusted.

“A signal conditioning device is applied to a video signal conversion device” includes the case where the signal conditioning device is applied as part of the video signal conversion device, and the signal conditioning device is used as a separate device from the video signal conversion device to It also includes cases where it is applied to receive a signal from a signal conversion device.

[2] The input video signal is a signal containing a first number of horizontal lines, which are signal groups separated by a horizontal synchronizing signal in each frame, and the length of the horizontal lines is determined by the first length. ,
The video signal conversion device has a conversion unit that generates an intermediate video signal based on the input video signal,
the intermediate video signal is a signal containing a second number of horizontal lines, which are a signal group separated by a horizontal synchronizing signal in each frame, and the length of the horizontal lines is determined by the second length;
The predetermined number is the second number of lines,
The reference value is the second length, and the adjusting section adjusts the timing of a horizontal synchronization signal for the intermediate video signal generated by the converting section to form a part of the intermediate video signal. The signal adjustment device according to [1], wherein the output video signal is generated so that the lengths of a plurality of horizontal lines are increased or decreased from the reference value.

The signal conditioning apparatus of [2] converts an input video signal having a frame structure of a first length and a first number of lines into an intermediate video signal having a frame structure of a second length and a second number of lines. When the conversion unit performs scaling so as to generate An output video signal can be generated in which the line length is different from the reference value.

[3] The adjustment unit adjusts the amount of increase or decrease of each adjustment line to 0 relative to the difference between the length obtained by multiplying the reference value by the second number of lines and the length per frame of the intermediate video signal. The signal conditioner according to [2], wherein lengths of each of the plurality of adjustment lines are determined to be close to each other.

The signal conditioning device of [3] above is the length obtained by multiplying the reference value by the second number of lines (the length of time when it is assumed that the horizontal line with the length of the reference value is repeated for the second number of lines) , and the time length per frame of the intermediate video signal is about the same as the increase/decrease amount (difference from the reference value) of the final horizontal line expected when no adjustment is performed. The signal conditioning device can adjust the increase/decrease amount of each adjustment line in a distributed manner so as to be closer to 0 than the above difference.

If the value (difference) obtained by subtracting the "length per frame of the intermediate video signal" from the "length obtained by multiplying the reference value by the second number of lines" is positive, the amount of increase or decrease is less than 0. is the decrease amount of the "positive value" which is larger than the "subtracted value" (difference). If the value (difference) obtained by subtracting the "length per frame of the intermediate video signal" from the "length obtained by multiplying the reference value by the second number of lines" is negative, the amount of increase or decrease is equal to the above "subtracted value (difference) and less than 0 (that is, the amount of increase in the absolute value of the "negative value").

[4] The signal conditioning device according to any one of [1] to [3], wherein the adjustment section selects the plurality of adjustment lines only from the plurality of blank lines following the data line.

The signal adjustment device of [4] above is capable of performing adjustment by dividing an adjustment target into a plurality of blank lines without performing biased adjustment on only a specific line, and is capable of adjusting the length of the plurality of data lines. Adjustments can be made in a manner that has less impact on the data signal without forcing it to increase or decrease the intensity.

[5] The adjustment unit adjusts the lengths of any or all of the plurality of blank lines excluding the last blank line among the plurality of blank lines to an adjustment value smaller or larger than the reference value. Adjust the start timing of the final blank line by setting to
The signal conditioning device according to any one of [1] to [4], wherein the length of the final blank line is closer to the reference value than the reference value or the adjustment value.

In the signal adjustment device of [5] above, the adjustment unit adjusts the start timing of the final blank line so that the length of the final blank line matches the reference value or is shorter than the length of the remaining blank line. It can be brought close to the reference value. Therefore, in this signal conditioning device, even if some error occurs, the length of the final horizontal line is less likely to deviate greatly from the reference value.

[6] A video signal conversion device including the signal conditioning device according to any one of [1] to [5].

The above [6] video signal conversion device can produce at least the same effects as the above [1] signal adjustment device.

<First embodiment>
1-1. Overview of In-Vehicle System 1 FIG. 1 illustrates a video signal conversion device 10 including a signal conditioning device 50 according to the first embodiment. Further, FIG. 1 illustrates an in-vehicle system 1 to which the video signal conversion device 10 is applied. The in-vehicle system 1 is a system mounted in a vehicle (not shown), and includes an in-vehicle monitor 100 , an in-vehicle device 120 and a video signal conversion device 10 .

In the in-vehicle system 1 of FIG. 1 , a video signal (external video signal) output from the external device 190 is input to the input section 32 of the video signal conversion device 10 . The video signal conversion device 10 has a function of converting a video signal (external video signal) given from the external device 190 into an output video signal and outputting it to the in-vehicle monitor 100 via the output terminal 34 . When the video signal converter 10 outputs the output video signal via the output terminal 34 , this output video signal is input to the in-vehicle monitor 100 via the input section 103 . When the output video signal is input to the input unit 103, the in-vehicle monitor 100 can cause the display 102 to display a video (such as content displayed by the external video signal) based on the external video signal.

1-2. Basic Configuration and Basic Operation of External Device 190 The external device 190 is a device provided outside the vehicle-mounted monitor 100 and the vehicle-mounted device 120 . In the example of FIG. 1 , the external device 190 is a device external to the video signal conversion device 10 . In the example of FIG. 1, the external device 190 is a device different from any of the video signal conversion device 10, the in-vehicle device 120, and the in-vehicle monitor 100, and outputs a video signal (external video signal) to the video signal conversion device 10. It is a device that obtains The external device 190 may be a device capable of outputting a known format video signal and a known format audio signal. The external device 190 may be a mobile information terminal such as a smart phone or a tablet terminal, or may be another information terminal.

In the example of FIG. 1, an external device 190 is electrically connected to the video signal conversion device 10 via a signal line 192 (for example, an HDMI (High-Definition Multimedia Interface) cable or other known transmission system cable). there is Note that HDMI is a registered trademark. A signal output from the external device 190 is input to the input section 32 of the video signal conversion device 10 via the signal line 192 . In the representative example described below, the external device 190 is an HDMI source device capable of outputting a signal including a video signal conforming to the HDMI standard (hereinafter also referred to as HDMI signal).

1-3. Basic Configuration and Basic Operation of In-Vehicle Monitor 100 The in-vehicle monitor 100 is a device having a display 102 and capable of displaying an image on the display 102 based on a video signal input thereto. In the representative example of FIG. 1, the in-vehicle monitor 100 is a device including an input unit 103, an image generation unit 108, an image synthesis unit 101, a display 102, and the like. The display 102 is configured as a display device such as a liquid crystal display device, and can display various images such as moving images and still images. The type of display that constitutes the in-vehicle monitor 100 is not limited to a liquid crystal display device, and may be another type of display such as an organic EL display or a plasma display.

The input unit 103 is an interface to which the video signal from the video signal conversion device 10 is input. The video signal input to the input unit 103 is, for example, a digital video signal of a known transmission method (GVIF, LVDS, etc.) and is a serial signal.

The input unit 103 includes a terminal unit 103A and a conversion device 103B. 103 A of terminal parts are parts provided with several terminals which the signal from the video signal converter 10 inputs, and are comprised, for example as a connector. The conversion device 103B is a deserializer that converts an output video signal (serial signal) input to the terminal section 103A into a parallel signal.

The image generation unit 108 is a part that generates various images to be displayed on the display 102 . The video synthesizing unit 101 is a part that generates an image to be displayed on the display 102 . The video synthesizing unit 101 has a function of synthesizing the video generated by the video generating unit 108 and the video converted by the conversion device 103B.

The in-vehicle monitor 100 can communicate with each device via an in-vehicle communication line (not shown). This in-vehicle communication line is a communication line that performs multiplex communication using an IE-Bus (Inter Equipment Bus) method, a CAN (Controller Area Network) method, or other communication methods. In-vehicle monitor 100 displays an image on display 102 based on an image signal input to input unit 103 .

1-4. Basic Configuration and Basic Operation of In-vehicle Device 120 The in-vehicle device 120 is a device capable of outputting a video signal. In the example of FIG. 1, the in-vehicle device 120 is, for example, an in-vehicle navigation device. The in-vehicle device 120 may be an in-vehicle device that does not have a navigation function. The in-vehicle device 120 includes a control device, an audio output section, a storage section, a communication section, and the like, which are not shown. In-vehicle device 120 can output a video signal via signal line 194 . In the example of FIG. 1 , the signal line 194 is a signal line for transmitting a video signal from the in-vehicle device 120 to the input section 31 of the video signal conversion device 10 . The video signal transmitted from the in-vehicle device 120 to the video signal conversion device 10 via the signal line 194 is, for example, a digital video signal of a known transmission method (GVIF (Gigabit Video InterFace), LVDS (Low Voltage Differential Signaling), etc.). , which is a serial signal.

The in-vehicle device 120 has a function of transmitting information via an in-vehicle communication line and a function of receiving information via the in-vehicle communication line. The in-vehicle device 120 can communicate with each device via the in-vehicle communication line. The in-vehicle device 120 may also have a function of operating a speaker (not shown) so as to output sound according to an audio signal input via a terminal (not shown). In the example of FIG. 1, the video signal conversion device 10 can also output an audio signal to the terminal section of the in-vehicle device 120 . The in-vehicle device 120 can operate such that the speaker emits sound corresponding to the audio signal input from the video signal conversion device 10 .

1-5. Configuration and Features of Video Signal Conversion Apparatus 10 The video signal conversion apparatus 10 generates an output video signal suitable for display on the in-vehicle monitor 100 from a video signal supplied from the external device 190 , and outputs this output video signal from the output terminal 34 . It is a device that can output. The video signal conversion device 10 has an input section 31, an input section 32, an output terminal 34, a switching device 20, a signal conversion section 16, and the like.

The input section 31 is a section to which a video signal is input, and is a first input terminal section having a plurality of terminals. In the example of FIG. 1 , a video signal output from the in-vehicle device 120 is input to the input section 31 . The input section 32 is a section to which a video signal is input, and is a second input terminal section having a plurality of terminals. In the example of FIG. 1 , a video signal (external video signal) output from the external device 190 and transmitted via a signal line 192 in a wired manner is input to the input unit 32 . Note that the input unit 32 may be a receiving unit that receives an external video signal wirelessly transmitted from the external device 190 .

The output terminal 34 is a portion that outputs a video signal, and is an output terminal section that includes a plurality of terminals. In the example of FIG. 1 , the video signal output from the output terminal 34 is input to the input section 103 of the onboard monitor 100 via the signal line 198 . The video signal output from the output terminal 34 is, for example, a digital video signal of a known transmission method (GVIF, LVDS, etc.) and is a serial signal.

The switching device 20 outputs from the output terminal 34 an output video signal generated based on a video signal (external video signal) from the external device 190 , and outputs a video signal input from the in-vehicle device 120 from the output terminal 34 . It is a device that can switch between an output operation and an output operation. The switching device 20 outputs an output video signal based on the external video signal from the output terminal 34 when the first condition is satisfied. The switching device 20 causes the video signal input from the in-vehicle device 120 to be output from the output terminal 34 when a second condition different from the first condition is established. The first condition and the second condition can be various conditions. For example, the first condition may be that a predetermined input has been made in the in-vehicle device 120 .

The signal conversion section (signal generation section) 16 is a section that generates an output video signal suitable for display on the in-vehicle monitor 100 from the video signal provided from the external device 190 . The output video signal generated by the signal converter 16 is output to the signal line 42 and transmitted to the switching device 20 via the signal line 42 .

The signal converter 16 has, for example, a configuration as shown in FIG. In the example of FIG. 2 , the signal converter 16 comprises a signal converter 62 , a signal conditioner 50 and an output 64 . In a typical example, the signal converter 16 functions as a signal converter that converts an HDMI signal conforming to the HDMI standard into a GVIF signal conforming to the GVIF standard.

The signal conversion section 62 is a timing controller having an arithmetic function and a signal conversion function. The signal converter 62 includes a first converter 62A and a second converter 62B. The first converter 62A is a deserializer that converts an input serial signal into a parallel signal. The first conversion unit 62A converts an HDMI standard external video signal (serial signal) input from the external device 190 into a parallel signal. The converted signal (parallel signal) output by the first converter 62A includes a vertical synchronization signal (V-SYNC), a horizontal synchronization signal (H-SYNC), a data enable signal (DE), a clock signal (CLK), data It includes signals (R signal, G signal, B signal), etc., and the first converter 62A outputs these signals in parallel and supplies them to the second converter 62B.

The second converter 62B functions as a scaler that scales the input video signal. The second converter 62B performs scaling on the parallel signal input from the first converter 62A (deserializer) as an input video signal to generate an intermediate video signal (output video signal before adjustment). A scaling method will be described later. The intermediate video signal generated by the second converter 62B includes a vertical synchronization signal (V-SYNC), a horizontal synchronization signal (H-SYNC), a data enable signal (DE), a clock signal (CLK), a data signal (R signal, G signal, B signal), etc. are parallel signals. The second converter 62B outputs these signals in parallel.

The signal adjustment device 50 adjusts the intermediate video signal (output video signal before adjustment) generated by the second converter 62B to generate an output video signal (output video signal after adjustment). In the example of FIG. 1 , signal conditioner 50 includes conditioner 52 . The adjuster 52 adjusts the horizontal synchronization signal (H-SYNC) in the intermediate video signal (output video signal before adjustment) generated by the second converter 62B. A signal conditioning method by the signal conditioning device 50 will be described later.

The output unit 64 is configured by a serializer that converts an input parallel signal (output video signal after adjustment) into a GVIF serial signal. The output unit 64 outputs a vertical synchronization signal (V-SYNC), a data enable signal (DE), a clock signal (CLK), a data signal (R signal, G signal, B signal) and the adjusted horizontal synchronization signal (H-SYNC) output from the signal adjustment device 50 are input in parallel. The output unit 64 generates a GVIF serial signal from these parallel signals and outputs it to the signal line 42 .

The video signal conversion device 10 also includes a communication terminal (not shown) connected to the vehicle-mounted communication line and a terminal (not shown) for outputting an audio signal. The video signal conversion device 10 has a function of transmitting information to an in-vehicle communication line via the communication terminal, and also has a function of receiving information transmitted via the in-vehicle communication line via the communication terminal. The video signal conversion device 10 can communicate with each device via the in-vehicle communication line.

1-6. Specific Operation of Signal Conversion Unit The following description relates to details of the operation of the signal conversion unit 16 .
The video signal conversion device 10 receives the HDMI standard external video signal (serial signal) output from the external device 190 by the first conversion unit 62A. When receiving an external video signal (serial signal) from the external device 190, the first conversion unit 62A configured as a deserializer converts the external video signal into a parallel signal, and converts the external video signal into a vertical synchronization signal ( V-SYNC), horizontal synchronization signal (H-SYNC), data enable signal (DE), clock signal (CLK), and data signals (R signal, G signal, B signal) are output in parallel. The parallel signal output by the first converter 62A corresponds to an example of an input video signal.

A vertical synchronizing signal (V-SYNC) included in the video signal is a signal that defines a division of one frame (one screen) in any of the input video signal, the intermediate video signal, and the output video signal. A vertical synchronizing signal defines the period of each frame. The input video signal, the intermediate video signal, and the output video signal all have the same vertical synchronization signal frequency. That is, each frame of the intermediate video signal and the output video signal is generated in synchronization with each frame of the input video signal. A horizontal synchronizing signal (H-SYNC) is a signal that defines each division of a plurality of lines (scanning lines) in each frame. A "group of signals in each period separated by a horizontal synchronizing signal" is a group of signals of each scanning line, which is a horizontal line. The period of one horizontal line is the period from the output timing of the horizontal synchronizing signal corresponding to that horizontal line (falling timing in the examples of FIGS. 4 and 5) to the output timing of the next horizontal synchronizing signal. Horizontal line length means the length of time from the start to the end of a horizontal line. Specifically, the length of a horizontal line is the length of time (time) from the output timing of the horizontal synchronizing signal corresponding to that horizontal line to the output timing of the next horizontal synchronizing signal. Each horizontal line (a signal group in each period separated by the horizontal synchronizing signal) includes a data enable signal, data signals (R signal, G signal, B signal), etc. in each period separated by the horizontal synchronizing signal.

The second converter 62B performs scaling on the parallel signal input from the first converter 62A (deserializer) as an input video signal by a known method. In a representative example, as shown in the left diagram of FIG. 3, the input video signal supplied to the second conversion section 62B is such that in each frame, horizontal lines (first horizontal lines) separated by the horizontal synchronization signal are the first horizontal lines in one frame. One line number L1 is included, and the length of the first horizontal line (first length T1) is determined based on the first clock number H1 (horizontal clock number H1). The frequency (clock frequency) of the clock signal (CLK) of the input video signal is the first frequency f1. The second conversion unit 62B, which functions as an example of a conversion unit, performs scaling on such an input video signal, and produces an intermediate video signal (output before adjustment) in which the frame size is changed based on the input video signal. video signal).

As shown in the right diagram of FIG. 3, the scaled intermediate video signal generated by the second conversion unit 62B has a horizontal line (second horizontal line) separated by a horizontal synchronization signal in each frame as the second horizontal line in one frame. The length (second length T2) of this horizontal line (second horizontal line) is determined based on the second clock number H2 (horizontal clock number H2). The second number of lines L2 corresponds to an example of the predetermined number. In this embodiment, the second length T2 is the reference value. Therefore, in the following description, it is also called the reference value T2. The second length T2 (reference value T2) is the length of the second clock number H2 of the intermediate video signal, specifically, the time of H2 clocks of the intermediate video signal. The frequency (clock frequency) of the clock signal (CLK) of the intermediate video signal is the second frequency f2. That is, T2=H2/f2. The second converter 62B sets the second frequency f2 so that the frame rate of the input video signal and the frame rate of the intermediate video signal are equal. As shown in the right diagram of FIG. 3, the intermediate video signal is generated after a plurality of blank lines (A2 in the right diagram of FIG. 3) that do not contain pixel data in a predetermined number L2 of horizontal lines (scanning lines) in one frame. , a plurality of data lines containing pixel data (A3 in the right figure of FIG. 3) continue, and then a plurality of blank lines not containing pixel data (A4 in the right figure of FIG. 3) continue to the final horizontal line. ing.

In any video signal, the data signal for each pixel is an RGB signal for determining the color of each pixel, and the data signal is also referred to as an RGB signal in the following description. The RGB signals (data signals) consist of an R signal that determines the degree of brightness of R (red), a G signal that indicates the degree of brightness of G (green), and a degree of brightness of B (blue). and a B signal indicative of A data enable signal for each pixel is a signal that determines whether to enable or disable the RGB signal for each pixel. Pixel data is data that can specify the color of a pixel by RGB signals, and is data for displaying a part of an image. Specifically, the pixel data are RGB signals (R signal, G signal, B signal) during a period in which the data enable signal is a valid signal (H level signal in the examples of FIGS. 4 and 5). A horizontal line that does not contain pixel data is a horizontal line whose data enable signal is set to an invalid signal (L level signal in the examples of FIGS. 4 and 5) during the entire period of the horizontal line. A horizontal line containing pixel data means that the data enable signal is a valid signal (H level signal in the examples of FIGS. 4 and 5) and the data enable signal is a valid signal in at least a partial period of the horizontal line. It is a horizontal line in which the color of each pixel is specified by RGB signals (R signal, G signal, B signal) in a period. In the example of FIG. 5, in the horizontal line, the period corresponding to one pixel is the period from the rise of one clock signal to the rise of the next clock signal. Although RGB signals are exemplified as data signals in this embodiment, color difference signals may be employed.

In this embodiment, the length of each data line in all the data lines in the intermediate video signal is set to the reference value T2. The lengths of horizontal lines other than the final horizontal line in the intermediate video signal are also set to the reference value T2. That is, in the intermediate video signal, the length (time) of each horizontal line in all horizontal lines (scanning lines) other than the final horizontal line is equal to the second clock number H2 of the clock signal with the second frequency f2. length. However, in one frame of the intermediate video signal, the end timing of the final horizontal line is determined by the output of the vertical synchronizing signal of the next frame. Therefore, the length of the final horizontal line (scanning line) may increase or decrease from the length corresponding to the second clock number H2.

FIG. 4 shows a signal (1 frame signal) conceptually. FIG. 5 shows a signal (one horizontal line (one scanning line ) is conceptually shown. A signal of one frame is included in the period from the output of one vertical synchronization signal to the output of the next vertical synchronization signal (the period from the falling edge of the vertical synchronization signal to the next falling edge in the example of FIG. 4), They are a vertical synchronizing signal, a horizontal synchronizing signal, a data signal, a data enable signal, a clock signal, and the like. In the example of FIG. 4, the number of horizontal lines in one frame (the number of lines L2) is 525 lines, the number A2 of blank lines before the data lines in one frame is 39 lines, and the number of data lines in one frame is A3 is 480 lines, and the number of blank lines A4 after the data lines in one frame is 6 lines. One horizontal line is included in the period from the output of one horizontal synchronizing signal to the output of the next horizontal synchronizing signal (the period from the falling edge of the horizontal synchronizing signal to the next falling edge in the example of FIG. 5). horizontal synchronization signal, data signal, data enable signal, clock signal, etc. In the example of FIG. 5, the number of "intermediate video signal clocks" included in one horizontal line (a value indicating the number of dots in one line) is 1000, and the number of effective pixels in one line (data enable signal is valid) is 1000. 800 is the number of clocks B3 indicating the number of pixels in the period used as a signal. In the example of FIG. 5, the second length T2 (reference value) is the length of the intermediate video signal for 1000 clocks, and H2=1000.

The signal converter 62 has a function of calculating a numerical value for adjusting the horizontal synchronization signal in addition to the function of performing the scaling described above. Specifically, the signal conversion unit 62 can calculate each numerical value as follows. The signal conversion unit 62 generates a value for specifying the difference between the length X 1 (time) obtained by multiplying the reference value T2 by the second number of lines L2 and the length X2 (time) per frame of the intermediate video signal. ΔH is obtained. The length of one frame of the intermediate video signal is the period of the vertical synchronization signal of the intermediate video signal. The length X1 is X1=T2*L2. If the length X1 is C1 clocks of the clock signal (CLK) of frequency f2 and the length X2 is C2 clocks of the clock signal (CLK) of frequency f2, then X1=C1/f2 and X2 =C2/f2. And ΔH is ΔH=C1−C2. That is, ΔH is the difference between the number of clocks corresponding to X1 and the number of clocks corresponding to X2. For example, if ΔH is positive, it means that the length of the final horizontal line will be shorter than the length of the other horizontal lines (reference value T2) if no adjustment is made. In the representative example below, a case where ΔH is positive will be described as an example.

Here, when the frame rate of the input video signal is 59.9635 (FPS), and the resolution of the intermediate video signal including blank lines and the output video signal is 1000×525 (that is, H2=1000, L2=525 ) is taken as an example. Note that the frame rate corresponds to the frequency of the vertical synchronization signal. In this example, the total number of dots (H2×L2) per frame of the intermediate video signal and the output video signal is 1000×525=525000 dots. When generating 525000 dots at a frame rate of 59.9635 (FPS) and assigning one clock to each dot, the frequency of the clock signal must be 31.4808375 (MHz). However, due to restrictions such as the resolution of the signal converter 62, it is not always possible to generate a clock signal with a frequency of 31.4808375 (MHz). If the frequency of the clock signal (CLK) generated by the signal converter 62 is 31.48 (MHz), and the frame rate is 59.9635 (FPS), the total number of clocks per frame (total number of dots) is 31480000/59.9635=524986.0333. In this example, the total number of clocks (total number of dots) per frame is 524986 at a frequency of about 29 frames in 30 frames, and 524987 at a frequency of about 1 frame in 30 frames. In this example, focusing on a frame in which the total number of clocks (total number of dots) is 524986, ideally, the total number of dots (total number of clocks) should be 525000 dots. In the example of , there is a deviation of ΔH=525000-524986=14. For example, if H2 is 1000, the final horizontal line will have 986 dots (clocks). If such a situation occurs, if the tolerance of the monitor that provides the video signal is small (for example, if the tolerance for "deviation" with respect to the length of the horizontal line is 5 clocks or less), the monitor will Therefore, a horizontal line having a length within the allowable range may not be input, and an image may not be properly displayed on the monitor. Although the above problem is merely an example, the signal adjustment device 50 according to the present embodiment performs the following adjustment in order to deal with such problems.

The signal conversion unit 62 obtains the value of the following formula 1 based on the number A4 of the plurality of blank lines following the plurality of (A3) data lines in the intermediate video signal.

The value represented by Equation 1 is the smallest integer that is not less than ΔH/A4, specifically, an integer obtained by rounding up the decimal point of ΔH/A4. In the following description, Tw1 is a value that satisfies Expression 2 below.

Tw1 (that is, the value of Equation 1) can be calculated by reducing the length of each blank line including only A4 by the number of clocks, and the above deviation per frame (ΔH clocks). length) can be adjusted. Note that in the present embodiment, the final horizontal line is not an adjustment line, but a horizontal line whose length is not adjusted by the adjustment unit. The length of the final horizontal line is passively determined by the "final horizontal line start timing" and the "vertical sync signal timing" determined by adjusting a plurality of adjustment lines.

Furthermore, the signal conversion unit 62 obtains the value of the following equation (3).

In the following description, Tc is a value that satisfies Equation 4 below.

Tc (that is, the value of Equation 3) is the smallest integer not less than ΔH/Tw1, specifically, an integer obtained by rounding up ΔH/Tw1 to the decimal point. Then, the signal converter 62 obtains Vts from the formula Vts=(L2+1)-Tc using the above-described predetermined number L2. Vts is the starting line number of the adjustment line (scanning line) that reduces the length of the horizontal line by the length of Tw1 clocks. That is, in the present embodiment, in one frame including the L2 line, the horizontal line is repeated by Tw1 clocks from the Vts-th line to the line immediately before the final horizontal line (that is, the (L2-1)-th line). I'm thinking of shortening the length. Further, the signal conversion unit 62 uses the above-described second clock number H2 (the clock number for determining the reference value T2) to obtain Ht1 by the formula Ht1=H2-Tw1. Ht1 is the number of clocks specifying the length of the adjustment line. That is, the length of the adjustment line is the length of Ht1 clocks of the intermediate video signal. Note that in the example of the present embodiment, the final horizontal line (hereinafter also referred to as the final line) does not correspond to the adjustment line. The signal converter 62 then transmits the values Vts and Ht1 to the signal conditioner 50 .

The signal adjustment device 50 adjusts the intermediate video signal (output video signal before adjustment) generated by the second converter 62B to generate an output video signal (output video signal after adjustment). The output video signal is a signal obtained by adjusting the timing of the horizontal synchronizing signal with respect to the scaled intermediate video signal shown in the right diagram of FIG. Each signal other than the horizontal synchronizing signal in the output video signal can be the same as each signal in the intermediate video signal. For example, in the example of FIG. 2, the clock signal for the output video signal is the same as the clock signal for the intermediate video signal. Therefore, the frequency (clock frequency) of the clock signal of the output video signal is the same as the clock frequency (second frequency f2) of the intermediate video signal output from the second converter 62B. In the example shown in FIG. 2, the vertical synchronizing signal (V-SYNC) of the output video signal is the same as the vertical synchronizing signal (V-SYNC) of the intermediate video signal output from the second converter 62B. The vertical synchronizing signal (V-SYNC) of the signal may be a signal slightly delayed by a predetermined time with respect to the vertical synchronizing signal (V-SYNC) of the intermediate video signal. The number of horizontal lines (scanning lines) for each frame included in the output video signal is the same as the number of horizontal lines (second line number L2) for each frame of the intermediate video signal output from the second converter 62B. may be changed. The horizontal lines included in the output video signal have a length (second length T2) corresponding to the second number of clocks H2 of the intermediate video signal, except for some horizontal lines. Specifically, in the output video signal, at least the horizontal lines excluding the adjustment line and the final horizontal line have a length corresponding to H2 clocks of the intermediate video signal (second length T2). The length of the adjustment line is set to a length (adjustment value T3 to be described later) that is reduced from the length of the intermediate video signal for H2 clocks (second length T2). The length of the final horizontal line may be the length of the H2 clock of the intermediate video signal (the second length T2), or may be slightly different from the length T2.

In a representative example, the output video signal (video signal input to the output unit 64) obtained after the adjustment by the signal conditioning device 50 has a predetermined number L2 of horizontal lines per frame, similar to the intermediate video signal shown in FIG. In one frame, after a plurality of blank lines that do not contain pixel data (the same number as A2 in FIG. 3), there are a plurality of data lines that contain pixel data (the same number as A3 in FIG. 3). ), followed by a plurality of (same number as A4 in FIG. 3) blank lines that do not contain pixel data until the last horizontal line. Both the output video signal after adjustment by the signal conditioning device 50 and the intermediate video signal before adjustment include a plurality of data lines having a length of the reference value T2. The length of each data line in the line is the length of the H2 clock of the intermediate video signal.

In a typical example, the adjustment unit 52 constituting the signal adjustment device 50 selects a plurality of adjustment lines including a plurality of blank lines from a predetermined number L2 of horizontal lines included in each frame of the intermediate video signal, and selects a plurality of adjustment lines including a plurality of blank lines. is adjusted to a length smaller than the reference value T2. Specifically, the signal adjustment device 50 receives the above values Vts and Ht1 transmitted from the signal conversion unit 62, and based on these values, adjusts the adjustment line (the scanning line whose length of the horizontal line is to be adjusted). to select. More specifically, among the predetermined number L2 of horizontal lines in one frame of the intermediate video signal, the horizontal line immediately preceding the last horizontal line from the Vts-th horizontal line ((L2-1)-th horizontal line). is an adjustment line, and the timing of the horizontal synchronizing signal is adjusted so that the length of this adjustment line is T3, which corresponds to the clock Ht1 of the intermediate video signal. The length T3 corresponding to the clock Ht1 of the intermediate video signal corresponds to an example of the adjustment value. In the following description, the length T3 is also called an adjustment value T3. The actual length of the final horizontal line (L2th horizontal line) is passively determined by the timing of the vertical synchronization signal (frame switching timing).

In this way, the signal adjustment device 50 adjusts the lengths of the plurality of adjustment lines so as to reduce them to a length (adjustment value T3) smaller than the reference value T2 (the length of the H2 clock of the intermediate video signal). do. The intermediate video signal output by the second conversion unit 62B is adjusted to reduce the length of the plurality of adjustment lines from the reference value T2 to the adjustment value T3, and the video signal input to the output unit 64 is the output video. is a signal. Signals included in the output video signal (vertical synchronization signal (V-SYNC), horizontal synchronization signal (H-SYNC), data enable signal (DE), clock signal (CLK), data signals (R signal, G signal, Of the B signal)), signals other than the horizontal synchronization signal (H-SYNC) of the adjustment line and the final horizontal line can be the same as the intermediate video signal output from the second converter 62B.

In this way, the adjustment unit 52 of the signal adjustment device 50 sets the length of the plurality of data lines in the output video signal to the reference value T2 (the length of the H2 clock of the intermediate video signal), and adjusts the length of the plurality of data lines in the output video signal. The length of the adjustment line is adjusted to the adjustment value T3 (length corresponding to the number of clocks less than H2). By adjusting the length of a plurality of adjustment lines, the start timing of the final horizontal line in the output video signal can be adjusted. can be accelerated compared to the case without adjustment (case of FIG. 7). For example, as shown in FIGS. 4 and 6, each frame signal of the output video signal (a group of signals for each frame input to the output unit) includes a plurality of blank lines (A2 lines) that do not contain pixel data. This is followed by a plurality of data lines (A3 lines) containing data signals, followed by a plurality of blank lines (A4 lines) containing no pixel data until the final horizontal line. In FIG. 6, the second clock number H2 corresponding to the reference value T2 is set to 1,000. As shown in FIG. 6, in each frame, any one of a plurality of blank lines following a plurality of data lines has a length greater than the length corresponding to the reference value T2 (the length of 1000 clocks of the intermediate video signal). If the adjustment value T3 (the length of the intermediate video signal for 997 clocks) is adjusted to be shorter, the start timing of the horizontal synchronizing signal for the final horizontal line is advanced by the amount of the adjustment. The length of the final horizontal line is longer compared to the case without (see FIG. 7).

In the example of FIG. 6, the adjustment unit 52 selects the plurality of adjustment lines only from the plurality of blank lines following the plurality of data lines in each frame. Then, in the output video signal, the adjustment unit 52 determines the length of each of the plurality of horizontal lines of the plurality of remaining lines excluding the final horizontal line among the plurality of blank lines following the plurality of data lines as a reference value. Adjustment is made so that the adjustment value T3 is smaller than T2. In the example of FIG. 6, the plurality of blank lines following the plurality of data lines are six lines from 520th to 525th, the last horizontal line (final line) is the 525th horizontal line, and the remaining lines are , 520th to 524th lines. The adjustment lines are the 521st to 524th four lines that are part of the plurality of residual lines, and the length of each of these adjustment lines is the adjustment value T3 ( length of 997 clocks). Because of this adjustment, the "length of the final horizontal line", which is a value passively determined by the vertical synchronizing signal, has a difference from the reference value T2 that is greater than the above-mentioned "length for ΔH clocks". It is significantly smaller, and more specifically, it falls within a predetermined allowable range.

1-7. Example of Effect By adjusting the timing of the horizontal synchronization signal, the signal adjustment device 50 can adjust the length of each of the plurality of adjustment lines to a value larger or smaller than the reference value T2. In addition, since the signal adjustment device 50 can perform adjustment by distributing it to a plurality of adjustment lines, it is possible to prevent the adjustment from biasing only a specific horizontal line. It is easy to solve problems caused by

For example, the example of FIG. 7 is an example in which the intermediate video signal described above becomes the output video signal as it is. In the example of FIG. 7, for reasons such as resolution, the frequency of the clock signal after scaling cannot be set with high precision, and the original timing at which the final horizontal line should end (horizontal synchronization corresponding to the start of the final horizontal line) The timing at which time T2 (1000 clocks worth of time) has elapsed from the signal output timing) is shifted from the frame switching timing (the next vertical synchronization signal output timing). Specifically, the timing for frame switching arrives considerably before the timing at which the time T2 (time for 1000 clocks) elapses from the output timing of the horizontal synchronizing signal at the start of the final horizontal line, and as a result, The length of the final horizontal line is significantly shorter than the length of the other horizontal lines. In other words, originally, the point in time when the time T2 (reference value T2) has passed from the start of the final horizontal line (horizontal sync signal output timing) coincides with the frame switching timing (the next vertical sync signal output timing). Although it is desirable to do so, the frame switching timing arrives at a timing considerably earlier than the time T2 (reference value T2) has elapsed. For example, in the example of FIG. 7, the above ΔH is 14 (ΔH=1000-986), and the length of the final horizontal line (length of 986 clocks) is equal to the reference value (length of 1000 clocks). ) is greatly deviated from

On the other hand, according to the present invention, when the signal converter 62 generates the intermediate video signal as shown in FIG. 7, a plurality of adjustment lines can be set for adjustment. Specifically, the signal converter 62 detects the number of clocks (986) of the last horizontal line. Then, the signal conversion unit 62 calculates ΔH (ΔH=H2−Hw=1000−986=14) based on the second clock number H2 (H2=1000 in the example of FIG. 7) and the above equation of ΔH. Calculate Then, Tw1 is calculated based on the number of blank lines A4 (A4=6) shown in FIG. 4 and the like and the formula for Tw1 described above. Specifically, Tw1 is obtained by the following equation (5).

Tw1 is the smallest integer not less than ΔH/A4. Specifically, Tw1 is an integer obtained by rounding up the decimal point of ΔH/A4. Furthermore, the signal conversion unit 62 calculates Tc based on the above-described formula for Tc. Specifically, Tc is obtained by the following equation (6).

Tc is the smallest integer not less than ΔH/Tw1. Specifically, Tc is an integer obtained by rounding up the decimal point of ΔH/Tw1. Then, the signal conversion unit 62 uses the second number of lines (predetermined number) L2 (L2=525 in the example of FIG. 7) and the above-described Vts=(L2+1)−Tc formula (that is, Vts=(525+1) Vts (Vts=521) is obtained based on the equation of -5). Further, the signal conversion unit 62 obtains Ht1 (Ht1=997) by the formula Ht1=1000-3. The signal converter 62 then transmits the values Vts and Ht1 to the signal conditioner 50 . By obtaining these values, the signal conditioning device 50 obtains the L2- The length of the blank line up to the 1st (524)th horizontal line can be adjusted to the length of Ht1 (997) clocks (adjustment value T3). The length of the line is about the same as the length of Ht2 (998) clocks. Note that in this example, Ht2 is not a value actively determined by the signal conditioning device 50 performing a calculation, but a value determined passively. The value of Ht2 can be expressed by the formula H2-(ΔH-(Tw1×(Tc-1)).The value of Ht2 is obtained by adjusting the number of clocks (ΔH) that indicates the degree of deviation described above with a plurality of adjustment lines. The value obtained by subtracting the value (ΔH-(Tw1×(Tc-1)) obtained by subtracting the number of clocks (Tw1×(Tc−1)) indicating the degree of summation of the amount of increase/decrease in the above-mentioned second number of clocks H2. In this way, since the length deviation of ΔH clocks can be dispersed and adjusted by a plurality of adjustment lines, the length of the final line (final horizontal line) is the reference value T2 (1000 clocks length of minutes) can be suppressed, and a plurality of adjustment lines can be prevented from greatly deviating from the reference value T2.In addition, in the example of this embodiment, the last line does not correspond to the adjustment line. For example, in a monitor that provides an output video signal, if the allowable range of horizontal line length (allowable range of deviation from the reference value) is 5 clocks or less (that is, the reference value (1000 clocks If the allowable range is a deviation of 5 clocks or less from the length), ΔH is 14 without the above adjustment, so the length of the final horizontal line is as shown in FIG. However, if the adjustment described above is performed, the deviation from the reference value will be within 3 clocks or less for all horizontal lines, as shown in FIG. range can be met.

As shown in FIG. 3, the signal conditioning device 50 converts an input video signal having a frame structure with a first clock number H1 and a first line number L1 (left diagram in FIG. 3) into a second clock number H2 and a second When the signal conversion unit 62 performs scaling so as to generate an intermediate video signal (right diagram in FIG. 3) having a frame structure with the number of lines L2, some horizontal lines of the intermediate video signal generated by the signal conversion unit 62 It is possible to generate an output video signal in which the lengths of the plurality of adjustment lines are different from the reference value T2 by a simple adjustment of increasing or decreasing the length.

The adjustment unit 52 calculates the length X1 obtained by multiplying the reference value T2 by the second number L2 of lines (the length of time when it is assumed that the horizontal line having the length of the reference value T2 is repeated by the second number L2 of lines). ) and the temporal length X2 per frame of the intermediate video signal is the same as the increase/decrease amount of the final horizontal line (difference from the reference value T2) expected without adjustment. The signal adjustment device 50 can adjust the increase/decrease amount of each adjustment line in such a manner that it is closer to 0 than the above difference.

For example, in the example of FIG. 6, the signal conditioning device 50 performs the adjustment only on a plurality of blank lines following a plurality of data lines, so that the adjustment can be performed without increasing or decreasing the length of the data lines, and the pixel Data can be suppressed from being affected. For example, if the length of a blank line preceding a plurality of data lines is adjusted, the start timing of each of the subsequent data lines will deviate from the original timing due to the adjustment. Although the timing may need to be adjusted, such a problem does not occur if the method of this embodiment is adopted. Also, if the length is adjusted for a plurality of data lines, the data enable signal and the RGB signal are affected by the adjustment. . For example, as shown in FIG. 4, in a period of a plurality of blank lines following a plurality of data lines, substantially no data enable signal or RGB signal is output (state without detailed information). , the data enable signal and the RGB signals are less affected.

<Other embodiments>
The present disclosure is not limited to the embodiments illustrated by the above description and drawings. For example, the features of the embodiments described above or below can be combined in any consistent manner. Also, any feature of the embodiments described above or below may be omitted if not explicitly indicated as essential. Furthermore, the embodiments described above may be modified as follows.

In the above-described embodiment, the signal conversion unit 62 is provided with the first conversion unit 62A and the second conversion unit 62B, and the second conversion unit 62B functions as "a conversion unit that generates an intermediate video signal based on an input video signal". It works, but is not limited to this example. For example, in the signal conversion section 62, the first conversion section 62A and the second conversion section 62B may be configured integrally. It may be configured as one device having the functions of the part 62B. In this example, the video signal input to the signal converter 62 corresponds to the input video signal. In this example, the signal conversion unit 62 functions as a “conversion unit that generates an intermediate video signal based on an input video signal” and outputs a signal similar to the intermediate video signal output by the above-described first conversion unit 62A. You may Further, in the above-described embodiment, the parallel transmission method in which parallel signals are transmitted from the signal conversion unit 62 to the output unit 64 is used between the signal conversion unit 62 and the output unit 64. However, the serial transmission method is used. may In this case, the serial signal transmitted from the signal conversion section 62 to the output section 64 may be adjusted on the adjustment line by the same adjustment method as the adjustment section 52 described above.

Although the above embodiments use the example of adjusting the timing of the horizontal sync signal to decrease the length of the adjustment lines, the timing of the horizontal sync signal is adjusted to increase the length of the horizontal lines. may For example, if .DELTA.H is negative, the timing of the horizontal sync signal may be adjusted to increase the length of the adjustment lines. In this case, part or all of the "plurality of residual lines" excluding the final line among the "plurality of blank lines following the plural data lines" are used as adjustment lines, and the length of these adjustment lines is reduced from the reference value T2. should be adjusted to increase The amount of increase in the adjustment line in this case is a value smaller than the length of |ΔH| clocks of the intermediate video signal.

The phrase "the signal conditioning device is applied to the video signal conversion device" includes the case where the signal conditioning device 50 is applied as part of the video signal conversion device 10 as in the above-described embodiment. However, it also includes a case where the signal conditioning device is configured as a separate device from the video signal conversion device and applied to receive a signal from the video signal conversion device. For example, in the video signal conversion device 10 of FIG. 1, the signal adjustment device 50 is configured as a device external to the video signal conversion device 10, and the intermediate video signal generated by the signal conversion unit 62 is converted to the signal adjustment device 50 by the video signal conversion device. 10 may be adjusted externally to produce the output video signal.

In the example of FIG. 6, the adjustment unit 52 adjusts the 521st to 524th horizontal lines forming part of the plurality of remaining horizontal lines excluding the final horizontal line in the plurality of blank lines following the plurality of data lines. The length is adjusted to an adjustment value T3 (a length of 997 clocks) that is different from the reference value T2 (a length of 1000 clocks). is a value close to the reference value T2 and other than the reference value T2 (a length of 998 clocks), but the present invention is not limited to this example. For example, as shown in FIG. 8, other adjustment lines may be adjusted so that the length of the final horizontal line is equal to the reference value T2 (length of 1000 clocks). When performing the adjustment as shown in FIG. 8, each value can be calculated as follows. In this example as well, the signal converter 62 detects the final horizontal line clock number (986) in the same manner as in the first embodiment. Then, the signal converter 62 calculates ΔH (ΔH=H2−Hw) by the same method as in the first embodiment. ΔH is 14 in the example of the intermediate video signal in FIGS. Further, the signal conversion unit 62 obtains Tw1 based on the number A4 of a plurality of blank lines following the plurality of (A3 in FIG. 3) data lines in the intermediate video signal. In this example, Tw1 is a value that satisfies Expression 7 below.

Specifically, Tw1 is a number obtained by rounding up ΔH/(A4-1) to the decimal point. Tw1 is 3 in the example of the intermediate video signal in FIGS. Furthermore, the signal converter 62 obtains Tc. Tc is a value that satisfies Expression 8 below.

Specifically, Tc is a number obtained by rounding up the decimal point of ΔH/Tw1. Tc is 5 in the example of the intermediate video signal in FIGS. Then, the signal conversion unit 62 obtains Tw2 by the formula Tw2=ΔH−(Tw1×(Tc−1)). Tw2 is 2 in the examples of FIGS. Then, the signal converter 62 uses the above-mentioned predetermined number L2 to find Vts by the formula Vts=(L2+1)-(Tc+1). Vts is 520 in the examples of FIGS. Vts is the starting line number of the adjustment line (scanning line) whose length is reduced by Tw1 clocks. Further, the signal conversion unit 62 uses the above-described second clock number H2 to obtain Ht1 by the formula Ht1=H2-Tw1. Ht1 is the number of clocks that determines the length of the adjustment lines other than the final adjustment line (horizontal line immediately before the final horizontal line), and these adjustment lines have a length of Ht1 clocks. Note that in this example, the final horizontal line is not the adjustment line. Further, the signal conversion unit 62 obtains Ht3 by the formula Ht3=H2-Tw2. Ht3 is the number of clocks that determines the length of the horizontal line immediately before the last horizontal line, and this adjustment line has a length of Ht3 clocks. The signal converter 62 then transmits the values Vts, Ht1, and Ht3 to the signal conditioner 50 . A signal conditioner 50 can receive these values and adjust the timing of the horizontal sync signal on the adjustment line as in FIG. In the example of FIG. 8, the signal conditioning device 50 sets the length of the horizontal line from Vts (520)th to Ht1 (997) two lines before the last horizontal line (523rd) in one frame of the output video signal to Ht1 (997). Adjust to clock length. In this example, the length (time) of Ht1 (997) clocks is the adjustment value T3. Then, the signal adjustment device 50 adjusts the length of the horizontal line immediately before the final horizontal line (524th) to the length of Ht3 (998) clocks. In this example, the length (time) of Ht3 (998) clocks is the adjustment value T4. That is, the signal conditioner 50 handles two types of adjustment values T3 and T4. In this way, since the deviation of ΔH(14) clocks is adjusted up to one before the final horizontal line, the length of the final horizontal line is equal to the reference value T2 (length of 1000 clocks). be the same. In the example of FIG. 8, the signal conditioning device 50 can set the length of the final horizontal line (final blank line) to the reference value T2 or a value close to the reference value T2. It is possible to make it more difficult for the problem caused by the large deviation from the reference value T2 to occur. For example, even if the frame rate of the input video signal should be 59.9635 (FPS) as described above, it may slightly fluctuate due to external factors such as temperature and power supply fluctuations. For example, when the frame rate of the input video signal fluctuates from 59.9635 (FPS) to 59.964 (FPS) and the clock signal (CLK) is generated at the frequency of 31.48 (MHz) described above, The total number of dots per frame is 31480000/59.964=524981.657, and ΔH may change from 14 to 19 as described above. If such a situation occurs, in the example shown in FIG. 6, the length of the final line will change from the length of 998 clocks to the length of 993 clocks. clock length) is off by 5 clocks or less). On the other hand, if the other adjustment lines are adjusted so that the final line has the reference value T2 as shown in FIG. , and can satisfy the above-mentioned allowable range.
Note that the above example is merely an example, and various methods can be adopted for allocating the increase/decrease value corresponding to ΔH (14 in the example of FIG. 8).

In the example of FIG. 6, the adjustment unit 52 sets a part of the "remaining plurality of horizontal lines" excluding the final horizontal line among the plurality of blank lines following the plurality of data lines as adjustment lines. All of the "remaining horizontal lines" may be adjusted lines. In any case, by adjusting the length of a plurality of adjustment lines, the length of the final horizontal line may be approximately the same as the reference value T2 (the length of H2 clocks), and the length of each adjustment line may be a value close to the reference value T2.

In the examples of FIGS. 6 and 8, the horizontal lines (adjustment lines) whose lengths are to be adjusted are selected from only blank lines, but some data lines may be included in the adjustment lines. For example, the last data line of a plurality of data lines is set as one of the adjustment lines, and the period after the data signal is changed without changing the start timing of the last data line or the period of the data signal (period of the RGB signal). Adjustments may be made to increase or decrease (period of B4 clock in FIG. 5). Alternatively, as shown in FIG. 9, the data line before the last data line among the plurality of data lines may be the adjustment line. Alternatively, the plurality of adjustment lines may be selected only from the plurality of data lines, and selected only from the plurality of blank lines (blank lines with the line number A2 in FIGS. 3 and 4) preceding the plurality of data lines. may be selected from a front blank line and a plurality of data lines. In addition, when the adjustment line is selected from multiple blank lines or multiple data lines on the front side, if there is a data line after the adjustment line, if the length of the adjustment line is increased or decreased, the length of the adjustment line will be increased or decreased. , the period of each data line is shifted. In this way, when adopting a method in which the period of each subsequent data line shifts as the length of the adjustment line increases or decreases, the period of the RGB signal and the data enable signal are adjusted so as to fit within the shifted period. period should be shifted. For example, if the length of the 518th data line is reduced as in the example of FIG. The period of the data line is shortened, but even if the period of any of the data lines is advanced or delayed in this way, the period of the RGB signals and the period of the data enable signal are adjusted so that they fit within the period of this data line. I wish I could.

In the example of FIG. 6, the adjustment line is adjusted so that the length of the final horizontal line is closer to the reference value T2 than the length of the adjustment line. An adjustment line may be adjusted such that the length of the line is comparable to all or part of the other adjustment lines.

In the above-described embodiment, the signal conditioning device 50 is configured as a separate device from the signal conversion unit 62 forming a part of the video signal conversion device 10, but is not limited to this example. For example, the signal converter 62 may function as a signal conditioner. In the embodiment described above, the signal converter 62 performs the calculation for determining the amount of increase or decrease, and the signal conditioner 50 operates to acquire information from the signal converter 62, but is not limited to this example. For example, the signal conditioning device 50 itself may perform calculations for determining the amount of increase or decrease, or the signal conditioning device 50 may have the function of calculating the above values Vts, Ht1, and Ht3.

In the above-described embodiment, the video signal conversion device 10 is configured as a single unit, but the video signal conversion device may be configured with a plurality of units.

In the example of FIG. 6 of the first embodiment, the last line is not an adjustment line and the lengths of all adjustment lines are set to the same adjustment value (length of 997 clocks). Also in the example of the form, the lengths of the plurality of adjustment lines may be set to two or more types of adjustment values.

In the embodiments described above, the final horizontal line is not an alignment line, but the final horizontal line may be an alignment line. That is, the adjuster may adjust the length of the final horizontal line.

In the description of the above embodiments, the description of the transmission of the audio signal has been omitted, but the transmission of the audio signal may be performed by an appropriate method, and the transmission path and the device configuration associated with the transmission are not particularly limited. For example, it may be output through a path different from the signal conversion unit 62 and the signal line 42 .

In the above-described embodiment, each of the input video signal, the intermediate video signal, and the output video signal is a progressive system signal that switches frames by a vertical synchronization signal, but each video signal is an interlace system signal. may be

In the above-described embodiment, the output timing of the horizontal synchronizing signal is the falling timing of the signal, but the rising timing of the signal may be the output timing of the horizontal synchronizing signal. In the above-described embodiments, the period corresponding to one pixel in the horizontal line was the period from the rise of one clock signal to the rise of the next clock signal. may be the period until the fall of the clock signal. Also, in the above example, one clock corresponds to one pixel, but a plurality of clocks may correspond to one pixel. Alternatively, one pixel may correspond to the period from the rising edge of one clock to the next falling edge, or one pixel may correspond to the period from the falling edge of one clock to the next rising edge. In addition, in the above-described embodiment, regarding the data enable signal, the H level signal is the valid signal and the L level signal is the invalid signal, but the L level signal is the valid signal and the H level signal is the invalid signal. There may be.

It should be noted that the embodiments disclosed this time should be considered as examples in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed this time, and includes all modifications within the scope indicated by the claims or within the scope equivalent to the claims. is intended.

1: In-vehicle system 10: Video signal conversion device 16: Signal conversion unit 20: Switching device 31: Input unit 32: Input unit 34: Output terminal 50: Signal adjustment device 52: Adjustment unit 62: Signal conversion unit 62A: First conversion Unit 62B: second conversion unit (conversion unit)
64: Output unit 100: In-vehicle monitor 101: Video synthesizing unit 102: Display 120: In-vehicle device 190: External device

Claims (5)

Outputs an output video signal containing a predetermined number of horizontal lines, which is a signal group for each line separated by a horizontal synchronizing signal and a signal group for each frame separated by a vertical synchronizing signal based on an input video signal to be input. A video signal conversion device that
generating the output video signal whose frame size is changed by scaling the input video signal whose frequency of the clock signal is the first frequency, and adjusting the timing of the horizontal synchronization signal of the output video signal; having a signal converter,
The predetermined number of horizontal lines included in the output video signal includes a plurality of data lines containing pixel data and having a reference length, followed by a plurality of blank lines containing no pixel data. continues until
The signal conversion unit makes the frequency of the vertical synchronization signal of the output video signal the same as the frequency of the vertical synchronization signal of the input video signal, and clocks the output video signal based on the frequency of the vertical synchronization signal of the input video signal. The frequency of the signal is set to a second frequency, the reference value is determined based on the second frequency, and the difference between the length obtained by multiplying the reference value by the predetermined number and the length per frame of the output video signal is calculated. calculating an identifying value ΔH, selecting a plurality of adjustment lines from the predetermined number of horizontal lines in each frame of the output video signal; is subtracted from the value distributed to the plurality of adjustment lines, and the length of each of the plurality of adjustment lines is adjusted so as to satisfy a predetermined allowable range . the input video signal is a signal containing a first number of horizontal lines, which are a signal group separated by a horizontal synchronizing signal in each frame, and the length of the horizontal lines is determined by the first length;
The signal conversion unit includes a conversion unit that generates an intermediate video signal based on the input video signal, and an adjustment unit that adjusts timing of a horizontal synchronization signal of the output video signal,
the intermediate video signal is a signal containing a second number of horizontal lines, which are a signal group separated by a horizontal synchronizing signal in each frame, and the length of the horizontal lines is determined by the second length;
The predetermined number is the second number of lines,
The reference value is the second length, and the adjusting section adjusts the timing of a horizontal synchronization signal for the intermediate video signal generated by the converting section to form a part of the intermediate video signal. 2. The video signal conversion device according to claim 1, wherein said output video signal is generated so that the lengths of a plurality of horizontal lines are increased or decreased from said reference value. The adjustment unit adjusts the amount of increase or decrease of each adjustment line so that it approaches 0 more than the difference between the length obtained by multiplying the reference value by the second number of lines and the length per frame of the intermediate video signal. 3. The video signal conversion device according to claim 2, wherein the length of each of the plurality of adjustment lines is determined. The video signal conversion device according to any one of claims 1 to 3, wherein the signal conversion section selects the plurality of adjustment lines only from the plurality of blank lines following the data line. The signal conversion unit sets the length of any one or all of the plurality of remaining blank lines excluding the final blank line among the plurality of blank lines to an adjustment value smaller or larger than the reference value. By adjusting the start timing of the final blank line,
5. The video signal conversion device according to claim 1, wherein the length of said final blank line is closer to said reference value than said reference value or said adjustment value.

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