JP2009162937A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent occurrence of flickering in a liquid crystal display device capable of performing pseudo impulse drive. <P>SOLUTION: This liquid crystal display device includes: a rate converting part 51 for doubling the frame rate of first image data input from a control part; a first gamma converting part 52 and a second gamma converting part 53 for making higher or lower the luminance level of image data output from the rate converting part 51; a switching part 54, to which light intensity image data output from the respective gamma converting parts 52, 53 and image data output from the rate converting part 51 are input, having a pseudo impulse driving function of outputting second image data by switching light and darkness; and a determination part 55 setting a determination condition that the first image data easily causing flickering matches when pseudo impulse drive is performed. When it is determined to match the determination condition concerning the first image data by the determination part 55, the switching part 54 outputs the image data intact, which is output from the rate converting part 51. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device having a function of reducing an hold effect by displaying an image on a liquid crystal panel by pseudo impulse driving.

  In the liquid crystal display device, unlike impulse display such as CRT, an image of the same frame is held and displayed for a predetermined time (for example, 1/60 second when the frame rate is 60 Hz). For this reason, even if the image is switched to the image of the next frame, the previous frame remains as an afterimage due to the retinal afterimage effect in the user's vision, and a hold effect occurs in which the moving image appears blurred when the moving image is displayed. Conventionally, in order to improve the image quality by reducing the hold effect, as a method of driving the liquid crystal panel, a second image of a plurality of frames is displayed for one frame of the original image (first image) displayed on the liquid crystal panel. A so-called pseudo impulse driving method is proposed. As a pseudo impulse driving method, for example, as disclosed in Patent Document 1, the display time of a normal first image is reduced, and a black screen or gray is displayed between the first image and the first image of the next frame. A method for inserting a screen (so-called black insertion or gray insertion), or a second image having a high luminance and a second image having a low luminance generated based on the first image are alternately displayed at high speed (hereinafter referred to as light / dark switching). Method) is known. In such a driving method, for example, the second image is switched and displayed on the liquid crystal panel at a frame rate that is twice the frame rate of the first image, so that the hold time effect is reduced by shortening the time for displaying the same image. For example, it is possible to make it possible to more clearly view a moving image in which scene change is fast and the change in image for each frame is large.

  By the way, at the time of double speed driving as described above, since images with different luminances are switched and displayed on the liquid crystal panel, the user may feel that the image quality is reduced due to flicker (flickering). The occurrence of flicker during double-speed driving is, for example, that the frame rate of the first image is 50 Hz, the first image is a high gradation raster image, or the first image is mainly a raster image of a personal computer or the like. This is particularly noticeable when it is included.

  Here, regarding the problem of occurrence of flicker at the time of such double speed driving, Patent Document 1 determines whether the first image is a moving image or a still image, and in the case of a moving image, black insertion is performed to improve the image quality. Is disclosed. However, Patent Document 1 does not disclose, for example, prevention of flicker when the frame rate of the first image is low. Further, Patent Document 1 does not disclose a configuration of a circuit or the like that can prevent occurrence of flicker particularly when performing light / dark switching in which two types of images having different lightness are displayed alternately.

  Patent Document 2 discloses a liquid crystal display device that reduces the hold effect by blinking a light source in a moving image. In this liquid crystal display device, when the video input is from a personal computer, it is determined that there are few moving images, and blinking is not performed, so that flicker is prevented. In Patent Document 3, in the liquid crystal display device that reduces the hold effect by turning on and blinking the light source, when the first image is a moving image, the ratio of the lighting period of the light source is lowered, thereby improving the image quality of the moving image. Is disclosed. However, in the liquid crystal display devices described in Patent Document 2 and Patent Document 3, in order to cause the light source to blink at high speed, it is necessary to use a highly responsive device such as an LED as the light source, which increases the manufacturing cost. It is a thing. Patent Document 2 and Patent Document 3 do not disclose a solution for the occurrence of flicker when images having different brightness levels are switched at high speed as described above.

Patent Document 4 discloses a liquid crystal that improves the image quality of both moving images and still images by changing the driving frequency, the driving method, and the backlight lighting method based on the determination result of whether the first image is a moving image or a still image. A display device is disclosed. However, in this liquid crystal display device, since the driving frequency and the driving method are changed depending on whether the first image is a moving image or a still image, the circuit configuration is complicated. Patent Document 4 does not disclose an effective solution for the occurrence of flicker when images having different brightness are switched at high speed in order to reduce the hold effect as described above.
Japanese Patent Laid-Open No. 2002-6818 Japanese Patent No. 3971922 Japanese Patent No. 3535799 JP 2002-91400 A

  The present invention has been made in view of the above problems, and can improve the image quality by pseudo impulse driving during normal moving image display, and automatically flickers under a predetermined condition in which the image is likely to generate flicker. An object of the present invention is to provide a liquid crystal display device capable of preventing the occurrence of the above.

  In order to achieve the above object, the invention of claim 1 outputs a liquid crystal panel configured to display an image with a plurality of pixels and image data to be displayed on the liquid crystal panel at a predetermined first frame rate. And a function of converting the first image data input from the control unit into image data having a second frame rate higher than the first frame rate, and outputting second image data based on the image data. A double-speed conversion unit; and a drive unit that drives each pixel of the liquid crystal panel based on the second image data output from the double-speed conversion unit, wherein the double-speed conversion unit converts the image into the second frame rate. A liquid having a pseudo impulse drive function by so-called light / dark switching for outputting data as second image data after performing a predetermined gamma conversion process. In the display device, the double speed conversion unit further includes a determination unit that determines whether or not a predetermined determination condition is matched with respect to the first image data input from the control unit, and the determination unit inputs from the control unit When it is determined that the determined first image data matches the determination condition, the image data converted to the second frame rate is output as the second image data as it is, thereby preventing occurrence of flicker. It is configured.

  According to a second aspect of the present invention, in the first aspect of the invention, the determination unit is input from a condition relating to a first frame rate of the first image data, a condition relating to the content of the first image data, and the control unit. The determination is performed on the first image data with the condition including at least one of the conditions regarding the input source information of the first image data as the predetermined determination condition.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the double speed conversion unit converts the first image data input from the control unit into image data of the second frame rate. A first gamma conversion unit that performs gamma conversion processing on the image data that has passed through the rate conversion unit based on a predetermined first gamma conversion table; and a predetermined second gamma conversion table for the image data that has passed through the rate conversion unit A second gamma conversion unit that performs gamma conversion processing based on the input, image data that has passed through at least the first gamma conversion unit, image data that has passed through the second gamma conversion unit, and image data that has passed through the rate conversion unit A switching unit capable of switching the input image data and outputting the second image data, and the switching unit is configured so that the determination unit performs the control. When it is not determined that the first image data input from the image data matches the determination condition, the image data that has passed through the first gamma conversion unit and the image data that has passed through the second gamma conversion unit are switched alternately. The pseudo impulse drive function is executed by outputting at a two-frame rate, and when the determination unit determines that the determination condition is satisfied with respect to the first image data input from the control unit, the rate conversion unit passes through the rate conversion unit. The pseudo impulse driving function is not executed by outputting the image data as it is at the second frame rate.

  According to the first aspect of the present invention, when the first image data matches a predetermined determination condition, the first image data or the image data whose frame rate is converted is output as it is. If flicker is highly likely to occur, the pseudo-impulse drive function is not executed, and an image can be displayed to automatically prevent flicker. When the possibility of occurrence of flicker is low, it is possible to view a clear and high-quality image with less moving image blur by the pseudo impulse drive function.

  According to the invention of claim 2, the predetermined determination condition includes a condition relating to at least one of the first frame rate of the first image data, the content of the first image data, and the input source information of the first image data. Therefore, for example, the first frame rate is less than a predetermined value, the first image data indicates a high gradation raster image, or the first image data is input from a personal computer. In such a case, when the pseudo impulse driving is performed, a case where flicker is likely to occur can be appropriately determined by the determination unit, and the occurrence of flicker can be effectively prevented.

  According to the invention of claim 3, when the first image data matches a predetermined determination condition, the switching unit that alternately switches between the two types of image data subjected to gamma conversion at the time of pseudo impulse driving in the double speed conversion unit. Since the image data that has passed through the rate converter is output as it is as the second image data, execution and non-execution of the pseudo impulse drive function according to the first image data with a relatively simple circuit configuration And the manufacturing cost of the liquid crystal display device can be reduced.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a liquid crystal display device according to this embodiment. The liquid crystal display device 1 is, for example, a television broadcast receiver. The liquid crystal display device 1 includes a liquid crystal panel 2, a tuner 3 that selects a signal input from an external antenna (not shown), a control unit 4 that controls each unit of the liquid crystal display device 1, and a control unit 4 The tuner 3 is controlled to control the tuner 3 to select a signal to be received by the tuner 3, and the frame rate of the first image data which is image data input from the tuner 3 via the controller 4 is set. Various speeds used by the control unit 4, a double speed conversion unit 5 having a function of converting and a so-called pseudo impulse drive function, a drive unit 6 for driving the liquid crystal panel 2 based on the second image data output from the double speed conversion unit 5 The storage unit 7 stores setting information and the like, and an external input unit 10 that can input image data from an external personal computer or an optical disk recorder, for example. For example, the control unit 4 can control whether to output image data based on a signal received by the tuner 3 to the double speed conversion unit 5 or to output image data input from the external input unit 10 to the double speed conversion unit 5. The liquid crystal display device 1 is configured to be able to view images from various image sources.

  The liquid crystal panel 2 includes a backlight (not shown) and a plurality of pixels (not shown) arranged in a matrix in the vertical and horizontal directions on the front surface thereof. Each pixel of the liquid crystal panel 2 is a liquid crystal element that changes the transmittance of light from the backlight according to the drive voltage when the drive voltage from the drive unit 6 is applied. In other words, the liquid crystal panel 2 is driven by the driving unit 6 at a gradation corresponding to the second image data output from the control unit 4 via the double speed conversion unit 5, and the gradation of the gradation of each pixel is driven. Thus, an image corresponding to the input signal selected by the tuner 3 is displayed. The drive unit 6 drives each pixel with a drive voltage corresponding to the output level of the second image data. In the present embodiment, the liquid crystal panel 2 is configured to be able to drive each pixel with, for example, 256 gradations of RGB, and is configured to display a so-called color image.

  The control unit 4 is configured by, for example, a microcomputer. The control unit 4 includes a signal processing unit 4a that processes the input signal input from the tuner 3 to generate image data. The signal processing unit 4a performs adjustment processing such as brightness and contrast of an image displayed on the liquid crystal panel 2 and gamma correction processing on an input signal, and displays the image on the liquid crystal panel 2 having a predetermined frame rate (for example, 50 hertz or 60 hertz). Image data of the image to be generated is generated. The generated image data is output from the control unit 4 and input to the double speed conversion unit 5.

  FIG. 2 shows the double speed converter 5. The double speed conversion unit 5 includes a rate conversion unit 51 to which image data is input from the control unit 4 as first image data, and a first gamma conversion unit 52 and a second gamma to which image data is input via the rate conversion unit 51. A conversion unit 53 and a switching unit 54 to which image data is input from the first gamma conversion unit 52 and the second gamma conversion unit 53 are provided. When the first image data is input, the rate conversion unit 51 is configured to output image data obtained by converting the frame rate by a factor of two. That is, in the present embodiment, when the first image data having a predetermined first frame rate (for example, 50 Hz or 60 Hz) is input, the rate conversion unit 51 converts the frame rate to twice, and the second Image data at a frame rate (for example, 100 Hz or 120 Hz) is output. The first gamma conversion unit 52 has a predetermined first gamma conversion table, and the second gamma conversion unit 53 has a predetermined second gamma conversion table. Each gamma conversion table corresponds to the brightness level (input level) of image data input to each gamma conversion unit 52, 53 and the brightness level (output level) of image data output from the gamma conversion unit 52, 53. The relationship is preset as a lookup table. In the present embodiment, the first gamma conversion table is set so that the output level corresponding to the input level is large and the image becomes bright, and in the second gamma conversion table, the output level corresponding to the input level is large, The image is set to be dark. For image data with the same input level, the output level in the first gamma conversion table and the output level in the second gamma conversion table are set so that the average of both output levels is substantially equal to the input level. The first gamma conversion unit 52 converts the luminance level of the image data output from the rate conversion unit 51 based on the first gamma conversion table, and outputs the image data having the higher luminance level to the switching unit 54. . The second gamma conversion unit 53 converts the luminance level of the image data output from the rate conversion unit 51 based on the second gamma conversion table, and outputs the image data whose luminance level has been lowered to the switching unit 54. .

  The switching unit 54 alternately switches between the image data having a high luminance input via the first gamma conversion unit 52 and the image data having a low luminance via the second gamma conversion unit 53 to switch the second. A pseudo impulse drive function is executed by outputting the image data to the drive unit 6. FIG. 3 shows a frame included in the first image data input to the double speed conversion unit 5, and a frame included in the second image data output from the double speed conversion unit 5 when the pseudo impulse drive function is executed. Is shown schematically. The switching unit 54 outputs the second image data at the second frame rate by switching the image data at a predetermined second frame rate (for example, 120 Hz when the first frame rate is 60 Hz). . As a result, as shown in the figure, the second image data includes image data of a high luminance (high luminance image data) and image data of a low luminance (low luminance image data) alternately for each frame. Will be included. That is, the double speed conversion unit 5 outputs the second image data for the image of 2 frames per first image data for the image of 1 frame (shown as an input image in the figure). Consists of one frame of high luminance image data (shown as a bright image in the figure) and one frame of low luminance image data (shown as a dark image in the figure) corresponding to the first image data for one frame image. . The drive unit 6 drives the liquid crystal panel 2 based on the second image data output from the double speed conversion unit 5, so that the liquid crystal panel 2 has light and darkness in the display time of the image of the first image data 1 frame. Two different frames of images are displayed. As described above, in the liquid crystal display device 1, the pseudo-impulse drive function by the light / dark switching is performed by the double speed conversion unit 5, so that the hold effect is less likely to occur in the user's vision. Accordingly, it is possible to make it possible to view a moving image having a large change in the image of each frame of the first image data with higher image quality.

  Here, in the present embodiment, the double speed conversion unit 5 is further provided with a determination unit 55, and the switching unit 54 is further input with image data of the second frame rate via the rate conversion unit 51. Has been. As illustrated in FIG. 2, the determination unit 55 receives the first image data and input source information related to the first image data from the control unit 4. Here, as the input source information, for example, data source information indicating whether the first image data is received by the tuner 3 or input from the external input unit 10, or the first image data If it is received by the tuner 3, it is the image data of which channel, or if it is input from the external input unit 10, it is input from an external personal computer. Or channel data indicating whether the input is from another external device or the like.

  The double speed conversion unit 5 determines whether the determination unit 55 matches a predetermined determination condition with respect to the first image data, and if it matches, the switching unit 54 determines the second frame rate via the rate conversion unit 51. By outputting the image data as the second image data, the pseudo impulse driving function is not performed. In the determination unit 55, determination conditions regarding the first image data are set in advance. The determination condition is set in advance so that the input condition is matched when there is a high possibility that flicker will occur when the pseudo impulse drive function by light / dark switching is performed based on certain first image data. As the determination conditions, for example, the first frame rate of the first image data is 50 Hz, the image of the first image data indicates a high gradation raster image, and the first image data is external. Three conditions are set: output from a personal computer connected to the input unit 10. The determination unit 55 determines whether or not each of the input first image data matches each of the determination conditions. If any one of the determination conditions is matched, the determination unit 55 is a flag indicating that fact. The determination signal is output to the switching unit 54.

  When the match determination signal from the determination unit 55 is input, the switching unit 54 is configured to output the image data that has passed through the rate conversion unit 51 as the second image data at the same second frame rate. Yes. FIG. 4 shows a frame included in the first image data input to the double speed conversion unit 5, and a frame included in the second image data output from the double speed conversion unit 5 when the pseudo impulse drive function is not executed. Is shown schematically. As shown in the figure, when the match determination signal is input, the switching unit 54 outputs the second image data at the second frame rate doubled by the rate conversion unit 51. Therefore, the double speed conversion unit 5 For each frame of first image data (shown as an input image in the figure), second image data corresponding to two frames of the same image as the first image data is output. When the match determination signal is no longer input from the determination unit 55, the switching unit 54 switches the bright image and the dark image again and executes the pseudo impulse drive function as described above.

  As described above, in the present embodiment, the frame rate is converted when the first image data matches a predetermined determination condition and there is a high possibility of flicker occurring when pseudo impulse driving is performed by switching between light and dark. Since the image data is output as it is, the image can be displayed without executing the pseudo impulse drive function, and flicker can be automatically prevented. On the other hand, when the possibility of occurrence of flicker is low, it is possible to view a clear and high-quality image with less moving image blur by the pseudo impulse drive function as in the conventional case. In addition, regarding the first frame rate of the first image data, the contents of the first image data, and the input source information of the first image data, the first image data when flicker is likely to occur when the pseudo impulse drive is performed is surely obtained. Since the determination conditions are set so as to match, it is possible to appropriately determine the case where flicker is likely to occur by the determination unit, and it is possible to more reliably prevent the occurrence of flicker.

  Further, in the liquid crystal display device 1, in the double speed conversion unit 5, the switching unit 54 that alternately switches between two types of light and dark image data during pseudo impulse driving passes through the rate conversion unit 51 when a match determination signal is input. The image data is output as second image data as it is. Accordingly, it is possible to switch between execution and non-execution of the pseudo impulse drive function according to the first image data by using the double speed conversion unit 5 as a relatively simple circuit configuration, and the manufacturing cost of the liquid crystal display device 1 can be reduced. It becomes possible to reduce.

  FIG. 5 shows a double speed conversion unit of the liquid crystal display device according to the second embodiment of the present invention. Hereinafter, in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and only the portions different from the first embodiment will be described. The second embodiment differs from the first embodiment in that the double speed conversion unit 105 of the liquid crystal display device is configured to perform a pseudo impulse drive function by a so-called black insertion method. The parts are configured in substantially the same manner as in the first embodiment.

  In the second embodiment, the double speed conversion unit 105 includes a rate conversion unit 51 and a determination unit 55 that are configured and function in substantially the same manner as in the first embodiment, and a black image that uses the image data output from the rate conversion unit 51 as a black image. The image data output from the insertion unit 152, the luminance adjustment unit 153 that changes the luminance level of the image data output from the rate conversion unit 51, and the black insertion unit 152 and the luminance adjustment unit 153 are input, and the second And a switching unit 154 capable of executing a pseudo impulse driving function by alternately switching at a frame rate. The predetermined determination condition set in the determination unit 55 is, for example, the first image data that is highly likely to cause flicker when the pseudo-impulse drive function using the black insertion method is executed, such as a condition related to the first frame rate. A condition that matches is set. The luminance adjustment unit 153 has a predetermined luminance adjustment lookup table, and based on the luminance adjustment lookup table, the luminance level of the image data is brighter according to the luminance level of the input image data. The brightness level is changed and output to the switching unit 154. Then, the switching unit 154 switches the video data input from the black insertion unit 152 and the luminance adjustment unit 153 alternately at the second frame rate (for example, 120 Hz), so that the black image frame and the high luminance image frame are switched. By outputting the second continuous image data alternately, it is possible to view a high-quality image by reducing the hold effect without significantly reducing the brightness of the image viewed through the liquid crystal panel 2. It is configured to be able to.

  Here, the switching unit 154 is configured so that the image data that has been output with the luminance level adjusted by the luminance adjusting unit 153 can be returned to the luminance level before the adjustment by the luminance adjusting unit 153. A brightness adjusting unit 154a is provided. When the determination unit 55 determines that the input first image data matches a predetermined determination condition, and outputs a match determination signal to the switching unit 154, the switching unit 154 is similar to the first embodiment. Only the image data output from the brightness adjustment unit 153 without using the image data input from the black insertion unit 152 is used to adjust the brightness level of the image data output from the brightness adjustment unit 153 by the brightness adjustment unit 154a. It is configured to output the second image data after returning to the luminance level before the adjustment by the unit 153. When the determination unit 55 outputs a match determination signal, the luminance adjustment unit 153 outputs the image data as it is to the switching unit 154 without performing luminance adjustment, and the image data is output from the double speed conversion unit 105 as second image data. It may be configured to be.

  As described above, in the second embodiment, the frame rate is converted when the first image data matches a predetermined determination condition and the possibility of occurrence of flicker is high when the pseudo impulse driving by the black insertion method is performed. Since the processed image data is output with substantially the same luminance and without black insertion, an image can be displayed without executing the pseudo impulse drive function, and flicker can be prevented. In addition, when the possibility of occurrence of flicker is low, it is possible to view a clear and high-quality image with less moving image blur by a pseudo impulse driving function using black insertion, as in the past.

  In addition, this invention is not limited to the structure of the said 1st Embodiment and 2nd Embodiment, A various deformation | transformation is possible suitably in the range which does not change the meaning of invention. For example, when the determination unit determines that the determination condition matches, the switching unit outputs the first image data as it is from the double speed conversion unit, and drives the liquid crystal panel 2 at a half frame rate at the time of pseudo impulse driving. It may be configured. Further, the determination unit may be configured to output a match determination signal only when it matches all set determination conditions with respect to the first image data. The determination condition may be settable.

1 is a block diagram showing an example of a liquid crystal display device according to a first embodiment of the present invention. The block diagram which shows the structure of the double speed conversion part of the said liquid crystal display device. The figure which shows the relationship between the 1st image data input into the said double speed conversion part, and the 2nd image data output from the same double speed conversion part according to the 1st image data at the time of a pseudo impulse drive. The figure which shows the relationship between the 1st image data input into the said double speed conversion part, and the 2nd image data output from the same double speed conversion part according to the 1st image data when not performing a pseudo impulse drive. The block diagram which shows the structural example of the double speed conversion part of the liquid crystal display device which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Liquid crystal panel 4 Control part 5 Double speed conversion part 6 Drive part 51 Rate conversion part 52 1st gamma conversion part 53 2nd gamma conversion part 54 Switching part 55 Determination part

Claims (3)

A liquid crystal panel configured to display an image by a plurality of pixels;
A control unit for outputting image data to be displayed on the liquid crystal panel at a predetermined first frame rate;
A double speed conversion unit having a function of converting the first image data input from the control unit into image data having a second frame rate larger than the first frame rate and outputting the second image data based on the image data;
A drive unit that drives each pixel of the liquid crystal panel based on the second image data output from the double speed conversion unit,
The double speed conversion unit has a pseudo impulse drive function by so-called light / dark switching that outputs the second image data after performing a predetermined gamma conversion process on the image data converted to the second frame rate. In
The double speed conversion unit further includes a determination unit that determines whether or not a predetermined determination condition is matched with respect to the first image data input from the control unit, and the determination unit is a first unit that is input from the control unit. When it is determined that the image data matches the determination condition, the image data converted to the second frame rate is output as it is as second image data, thereby preventing occurrence of flicker. A liquid crystal display device characterized by the above.   The determination unit includes at least one of a condition related to a first frame rate of the first image data, a condition related to the content of the first image data, and a condition related to input source information of the first image data input from the control unit. 2. The liquid crystal display device according to claim 1, wherein the determination is performed on the first image data using the condition including any one of the two as the predetermined determination condition. The double speed converter is
A rate conversion unit that converts the first image data input from the control unit into image data of the second frame rate;
A first gamma conversion unit that performs gamma conversion processing on the image data that has passed through the rate conversion unit based on a predetermined first gamma conversion table;
A second gamma conversion unit that performs gamma conversion processing on the image data that has passed through the rate conversion unit based on a predetermined second gamma conversion table;
At least image data that has passed through the first gamma conversion unit, image data that has passed through the second gamma conversion unit, and image data that has passed through the rate conversion unit are input, and the second image data is switched by switching the input image data. And a switching unit that can output as
The switching unit is
When the determination unit does not determine that the first image data input from the control unit matches the determination condition, the image data passes through the first gamma conversion unit and the image data passes through the second gamma conversion unit. By alternately switching and outputting at the second frame rate to execute the pseudo impulse drive function,
When the determination unit determines that the first image data input from the control unit matches the determination condition, the pseudo impulse is obtained by outputting the image data via the rate conversion unit as it is at the second frame rate. 3. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is configured not to execute a driving function.

Images