Driver and electro-optical device

Abstract

To provide a driver that can ensure the visibility of a warning light in a liquid crystal panel.SOLUTION: A driver 10 driving a segment electrode group of a liquid crystal panel 100 includes: a first segment driving circuit 21 that drives, in the segment electrode group, a first segment electrode EL1 for displaying a warning light; and a second segment driving circuit 22 that drives, in the segment electrode group, a second segment electrode EL2 for displaying a display object other than the warning light. The first segment driving circuit 21 outputs a first driving signal SG1 for displaying the warning light displayed by the first segment electrode EL1 at a higher contrast than the display object displayed by the second segment electrode EL2 driven by a second driving signal SG2 from the second segment driving circuit 22.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a driver, an electro-optical device, and the like. [Background technology]

[0002] Patent Document 1 discloses a display device for a work vehicle such as a tractor. In this display device, a liquid crystal display device for displaying vehicle speed, engine rotation speed, etc. is provided in the center of the display surface, and warning lights are arranged on the left and right of the center. In the event of an abnormality or malfunction, the warning lights are illuminated by light from an LED light source to notify the driver of the abnormality or malfunction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-78705 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the method of displaying warning lights using an LED light source provided separately from the backlight of the liquid crystal display device, as in Patent Document 1, a large number of LED elements are required to display various warning lights, leading to problems such as increased product costs. [Means for solving the problem]

[0005] One aspect of the present disclosure is a driver that drives a group of segment electrodes of a liquid crystal panel, and includes a first segment drive circuit that drives a first segment electrode of the group of segment electrodes for displaying a warning light, and a second segment drive circuit that drives a second segment electrode of the group of segment electrodes for displaying an object other than the warning light, wherein the first segment drive circuit is related to a driver that outputs the first drive signal that displays the warning light displayed by the first segment electrode with a higher contrast than the object displayed by the second segment electrode driven by a second drive signal of the second segment drive circuit.

[0006] Another aspect of the present disclosure relates to an electro-optical device including the driver described above and the liquid crystal panel. [Brief description of the drawings]

[0007] [Figure 1] 3 shows an example of the configuration of a driver and an electro-optical device according to the present embodiment. [Diagram 2] An example of a segment electrode in a liquid crystal panel. [Diagram 3] 3 shows a detailed configuration example of the driver and the electro-optical device according to the embodiment. [Figure 4] 13 is a configuration example in which a first segment drive circuit performs static drive and a second segment drive circuit performs duty drive. [Diagram 5] 4 shows an example of a signal waveform for static driving of the first segment driver circuit. [Figure 6] 4 shows an example of a signal waveform for duty driving of the second segment drive circuit. [Figure 7] 13 is a configuration example in which a first segment drive circuit performs static drive and a second segment drive circuit performs static drive. [Figure 8] Example of signal waveform for static drive using PWM signal. [Figure 9] Example of signal waveform for static drive using PAM signal. [Figure 10] 4 shows an example of a drive signal waveform for increasing the voltage amplitude of a first drive signal. [Figure 11] 3 shows an example of layout arrangement of a first segment drive circuit and a second segment drive circuit. [Figure 12] 3 shows an example of layout arrangement of a first segment drive circuit and a second segment drive circuit. [Figure 13] 1 shows an example of the configuration of an electro-optical device including a backlight having a light source and a light guide plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Preferred embodiments of the present disclosure will be described in detail below. Note that the embodiments described below do not unduly limit the contents described in the claims, and not all of the configurations described in the embodiments are necessarily essential components.

[0009] 1. Driver configuration example 1 shows an example of the configuration of a driver 10 of this embodiment. The driver 10 includes a first segment drive circuit 21 and a second segment drive circuit 22. An electro-optical device 200 of this embodiment includes the driver 10 and a liquid crystal panel 100. The electro-optical device 200 may further include a backlight, which will be described later.

[0010] The electro-optical device 200 is, for example, a display device that displays an image based on image data. The electro-optical device 200 is, for example, an in-vehicle display device such as a cluster display, which is a display of a meter panel, a center information display, a head-up display that displays a virtual image in the user's field of vision, or an electronic mirror. The in-vehicle display device is a display device mounted on a four-wheeled or two-wheeled automobile. Alternatively, the electro-optical device 200 may be a display device mounted on a moving body other than a car, such as a ship, a head-mounted display device called an HMD, a television device, or a display of an information processing device.

[0011] The liquid crystal panel 100 is an electro-optical panel and a display panel. The liquid crystal panel 100 is a panel driven by a static driving method, a duty driving method, or the like. Specifically, the liquid crystal panel 100 includes a first glass substrate, a second glass substrate, and liquid crystal. The liquid crystal is sealed between the first glass substrate and the second glass substrate. A segment electrode is provided on the first glass substrate, and a common electrode is provided on the second glass substrate. The driver 10 outputs a segment drive signal to the segment electrode. The driver 10 may also output a common drive signal to the common electrode. As a result, a voltage difference between the segment drive signal and the common drive signal is applied to the liquid crystal between the segment electrode and the common electrode. The segment electrode and the common electrode are transparent electrodes, for example, ITO (Indium Tin Oxide). The liquid crystal panel 100 is also provided with a backlight, as described later. For example, an edge-light type backlight can be used as the backlight. Specifically, the backlight has a light source and a light guide plate, and light from the light source is guided by the light guide plate provided on the rear side of the liquid crystal panel 100, for example.

[0012] The liquid crystal panel 100 includes a segment electrode group. The segment electrode group includes a first segment electrode EL1 for displaying a warning light and a second segment electrode EL2 for displaying an object other than the warning light. For example, the segment electrode group includes one or more first segment electrodes EL1 used to display a warning light and one or more second segment electrodes EL2 used to display an object other than the warning light.

[0013] FIG. 2 shows an example of a segment electrode of the liquid crystal panel 100. FIG. 2 shows an example of the liquid crystal panel 100 used in the meter panel of an automobile. ELA in FIG. 2 is an example of a segment electrode of a warning light. A warning light is a display object that is turned on to warn when, for example, some kind of malfunction or failure occurs in an automobile or the like, or when a user such as a driver performs an inappropriate operation. Specifically, ELA in FIG. 2 is a segment electrode for displaying warning lights related to fastening a seat belt, engine abnormality, battery abnormality, remaining gasoline, and opening and closing of a door. A warning light is displayed by an icon, symbol, or character that indicates a warning. On the other hand, ELB, ELC, ELD, and ELE in FIG. 2 are segment electrodes for displaying display objects other than warning lights. Display objects other than warning lights are display objects for conveying some kind of information to a user such as a driver by, for example, a display mode such as an on-off display or a gradation display. For example, ELB is a segment electrode of a display object that displays the speed of an automobile, and ELC is a segment electrode of a display object that displays the number of revolutions of an engine. In ELB and ELC, for example, gradation display is performed such that the areas showing the current speed, speeds below the RPM, and RPM are displayed darker, and the areas showing the speeds above the current speed and RPM are displayed lighter. ELD is a segment electrode of an 8-segment display, and ELE is a segment electrode of a guide display such as an arrow in simple navigation. Note that the segment electrodes of a warning light and the segment electrodes of displays other than a warning light are not limited to the example in Fig. 2, and segment electrodes of various shapes and configurations can be assumed.

[0014] The driver 10 is, for example, a circuit device called an IC (Integrated Circuit). For example, the driver 10 is an IC manufactured by a semiconductor process, a semiconductor chip in which circuit elements are formed on a semiconductor substrate, and, for example, a display driver that displays an image on the liquid crystal panel 100. The driver 10, which is a circuit device, is mounted on, for example, a glass substrate of the liquid crystal panel 100. For example, the driver 10 is mounted on a first glass substrate on which segment electrodes are provided. Alternatively, the driver 10 may be mounted on a circuit substrate, and the circuit substrate and the liquid crystal panel 100 may be connected by a flexible substrate.

[0015] The driver 10 of this embodiment, which drives the segment electrode group of the liquid crystal panel 100, includes a first segment drive circuit 21 and a second segment drive circuit 22. The driver 10 may also include a data storage circuit and a common drive circuit, as described below. This embodiment will be described mainly taking as an example a case in which two segment drive circuits, such as a first segment drive circuit 21 and a second segment drive circuit 22, are provided, but this embodiment is not limited to this, and three or more segment drive circuits may be provided.

[0016] The first segment drive circuit 21 drives the first segment electrode EL1 for displaying a warning light among the segment electrodes of the liquid crystal panel 100. For example, the first segment drive circuit 21 drives the first segment electrode EL1 by outputting a first drive signal SG1. The second segment drive circuit 22 drives the second segment electrode EL2 for displaying an object other than the warning light among the segment electrodes of the liquid crystal panel 100. For example, the second segment drive circuit 22 drives the second segment electrode EL2 by outputting a second drive signal SG2. For example, the driver 10 is provided with a first terminal (not shown) for outputting the first drive signal SG1 from the first segment drive circuit 21 and a second terminal (not shown) for outputting the second drive signal SG2 from the second segment drive circuit 22. The first terminal is connected to the first segment electrode EL1 of the liquid crystal panel 100, and the first drive signal SG1 from the first segment drive circuit 21 is output to the first segment electrode EL1 via the first terminal. The second terminal is connected to the second segment electrode EL2 of the liquid crystal panel 100, and the second drive signal SG2 from the second segment drive circuit 22 is output to the second segment electrode EL2 via the second terminal. The first terminal and the second terminal are, for example, pads of the driver 10, which is a circuit device. For example, in the pad region, a metal layer is exposed from the passivation film, which is an insulating layer, and this exposed metal layer constitutes a pad, which is a terminal of the driver 10. Note that the connection in this embodiment is an electrical connection. An electrical connection is a connection that allows an electrical signal to be transmitted, and is a connection that allows information to be transmitted by an electrical signal. The electrical connection may be a connection via a passive element, etc.

[0017] In this embodiment, the first segment drive circuit 21 outputs a first drive signal SG1 that displays a warning light displayed by the first segment electrode EL1 with a higher contrast than an object displayed by the second segment electrode EL2 driven by the second drive signal SG2 of the second segment drive circuit 22. For example, the warning light displayed by the first segment electrode EL1 is driven so as to have higher visibility than an object displayed by the second segment electrode EL2. For example, the first segment drive circuit 21 drives the first segment electrode EL1 of the warning light so that the first segment electrode EL1 for displaying the warning light described in ELA of FIG. 2 above is displayed with a higher contrast than the second segment electrode EL2 for displaying an object other than the warning light. Here, high contrast means, for example, a large difference in brightness between the brightness when the light is turned on and the brightness when the light is turned off. For example, a first drive signal SG1 is output such that the brightness difference between the brightness when the warning light displayed by the first segment electrode EL1 is turned on and off is larger than the brightness difference between the brightness when the object displayed by the second segment electrode EL2 is turned on and off. For example, in the case of normally white, lighting is a black display, and extinguishing is a white display. Therefore, in this case, driving is performed so that the luminance difference between the black display and the white display of the warning light is greater than the luminance difference between the black display and the white display of the display object other than the warning light. On the other hand, in the case of normally black, lighting is a white display, and extinguishing is a black display. Therefore, in this case, driving is performed so that the luminance difference between the white display and the black display of the warning light is greater than the luminance difference between the white display and the black display of the display object other than the warning light. In this way, the warning light is displayed with a higher contrast than the other display objects, and the luminance difference between the lighting and extinguishing is greater, so that the visibility of the warning light can be improved. Note that lighting can also be called an on display, and extinguishing can also be called an off display.

[0018] For example, suppose that the second segment drive circuit 22 drives the second segment electrode EL2 by a duty drive method. In this case, the first segment drive circuit 21 drives the first segment electrode EL1 by a static drive method, so that the warning light displayed by the first segment electrode EL1 is displayed with a higher contrast than the display object displayed by the second segment electrode EL2. Alternatively, suppose that the second segment drive circuit 22 drives the second segment electrode EL2 by a segment drive method such as PWM (Pulse Width Modulation) or PAM (Pulse Amplitude Modulation). In this case, the first segment drive circuit 21 drives the first segment electrode EL1 by a first drive signal SG1 having a pulse width wider than the pulse width (maximum pulse width) of PWM or a voltage amplitude larger than the voltage amplitude (maximum voltage amplitude) of PAM. As a result, the warning light displayed by the first segment electrode EL1 is displayed with a higher contrast than the display object displayed by the second segment electrode EL2. And, by displaying the warning light with a high contrast, it is possible to improve the visibility of the warning light.

[0019] 3 shows a detailed configuration example of the driver 10 and the electro-optical device 200 of this embodiment. In FIG. 3, the driver 10 includes a first segment drive circuit 21, a second segment drive circuit 22, a first common drive circuit 31, a second common drive circuit 32, data latches 41 and 42, a data storage circuit 50, and a control circuit 60. The driver 10 can also include a drive voltage supply circuit 70, an interface circuit 80, a first terminal TS1, a second terminal TS2, and common terminals TM1 and TM2. The driver 10 and the electro-optical device 200 are not limited to the configuration shown in FIG. 3, and various modifications can be made, such as omitting some of the components or adding other components.

[0020] The first segment drive circuit 21 outputs a first drive signal SG1 to drive the first segment electrode EL1 for displaying a warning light. The second segment drive circuit 22 outputs a second drive signal SG2 to drive the second segment electrode EL2 for displaying an object other than the warning light. As described above, the first segment drive circuit 21 outputs a first drive signal SG1 that displays the warning light displayed on the first segment electrode EL1 with a higher contrast than the object displayed by the second segment electrode EL2.

[0021] The first common drive circuit 31 drives the first common electrode corresponding to the first segment electrode EL1. For example, the first segment electrode EL1 and the first common electrode face each other. Specifically, the first common drive circuit 31 drives the first common electrode by outputting a common drive signal CM1 via a common terminal TM1. For example, the first drive signal SG1 is output to the first segment electrode EL1, and the common drive signal CM1 is output to the first common electrode, so that a voltage corresponding to the potential difference between SG1 and CM1 is applied to the liquid crystal between the first segment electrode EL1 and the first common electrode. This causes the on / off display of the warning light corresponding to the first segment electrode EL1. Here, the on / off display is, for example, a display of on or off. The second common drive circuit 32 drives the second common electrode corresponding to the second segment electrode EL2. For example, the second segment electrode EL2 and the second common electrode face each other. Specifically, the second common drive circuit 32 drives the second common electrode by outputting a common drive signal CM2 via the common terminal TM2. For example, the second drive signal SG2 is output to the second segment electrode EL2, and the common drive signal CM2 is output to the second common electrode, so that a voltage corresponding to the potential difference between SG2 and CM2 is applied to the liquid crystal between the second segment electrode EL2 and the second common electrode. This causes on / off display or gradation display of a display object such as an icon, number, letter, or symbol corresponding to the second segment electrode EL2.

[0022] The first terminal TS1 and the second terminal TS2 are terminals for outputting the first drive signal SG1 and the second drive signal SG2, and are realized, for example, by pads of the driver 10. The common terminals TM1 and TM2 are terminals for outputting the common drive signals CM1 and CM2, and are realized, for example, by pads of the driver 10.

[0023] The drive voltage supply circuit 70 supplies the first segment drive circuit 21, the second segment drive circuit 22, the first common drive circuit 31, and the second common drive circuit 32 with a drive voltage that is a drive power supply voltage for driving the liquid crystal panel 100. The first segment drive circuit 21 and the second segment drive circuit 22 generate and output a first drive signal SG1 and a second drive signal SG2 by selecting a drive voltage for the segment electrodes based on display data. The first common drive circuit 31 and the second common drive circuit 32 generate and output common drive signals CM1 and CM2 by selecting a drive voltage for the common electrodes under the control of the control circuit 60, etc. The common drive signals CM1 and CM2 are signals whose polarity is inverted, for example, every frame.

[0024] The data storage circuit 50 is a circuit for storing data for display and the like, and can be realized by a memory such as a RAM. The data storage circuit 50 stores data for display on the liquid crystal panel 100. The display data is, for example, on / off data or gray scale data for displaying objects corresponding to the segment electrodes. This display data is, for example, received from the processing device 300 via the interface circuit 80, and stored in the data storage circuit 50.

[0025] The data latches 41 and 42 latch the display data from the data storage circuit 50. The data latches 41 and 42, which are line latches or the like, latch the display data from the data storage circuit 50 based on a latch signal from, for example, the control circuit 60. The first segment drive circuit 21 generates and outputs a first drive signal SG1 based on the data latched in the data latch 41. The second segment drive circuit 22 generates and outputs a second drive signal SG2 based on the data latched in the data latch 42. The data latches 41 and 42 are realized by flip-flop circuits or the like.

[0026] The control circuit 60 is, for example, a logic circuit that operates based on a clock signal from an oscillator circuit (not shown). The control circuit 40 can be realized by, for example, an ASIC (Application Specific Integrated Circuit) circuit that is automatically placed and wired, such as a gate array, or a processor such as a CPU. The control circuit 60 controls the display timing or sets the operation of the driver 10. Specifically, the control circuit 60 writes display data, various setting data, command data, and the like received by the interface circuit 80 into a data storage circuit 50 realized by a RAM or the like.

[0027] The interface circuit 80 is a circuit that serves as an interface with the external processing device 300, and performs communication processing between the processing device 300 and the driver 10. For example, the interface circuit 80 receives various data such as command data and display data from the processing device 300. The interface circuit 80 can be realized by a serial interface circuit such as an I2C (Inter Integrated Circuit) type or an SPI (Serial Peripheral Interface) type.

[0028] The processing device 300 is, for example, a host device of the driver 10, and is realized by, for example, a processor or a display controller. The processor is, for example, a CPU or a microcomputer. The processing device 300 may be a circuit device composed of multiple circuit components. For example, in an on-vehicle electronic device, the processing device 300 may be an ECU (Electronic Control Unit).

[0029] As described above, the driver 10 of this embodiment that drives the segment electrode group of the liquid crystal panel 100 includes the first segment drive circuit 21 that drives the first segment electrode EL1 for displaying a warning light, and the second segment drive circuit 22 that drives the second segment electrode EL2 for displaying an object other than the warning light. The first segment drive circuit 21 outputs a first drive signal SG1 that displays the warning light displayed by the first segment electrode EL1 with a higher contrast than the object displayed by the second segment electrode EL2 driven by the second drive signal SG2 of the second segment drive circuit 22. As described above, in this embodiment, the first segment drive circuit 21 that drives the first segment electrode EL1 for displaying a warning light and the second segment drive circuit 22 that drives the second segment electrode EL2 for displaying an object other than the warning light are separately provided. By providing the first segment drive circuit 21 for the warning light in this manner, the first drive signal SG1 of the first segment drive circuit 21 makes it possible to display the warning light with a higher contrast than the object other than the warning light. This makes it possible to ensure the visibility of the warning light even when the warning light is displayed using the liquid crystal panel 100. Therefore, it is possible to provide a driver 10 who can display an object other than the warning light on the liquid crystal panel 100 and can display the warning light on the liquid crystal panel 100 with higher visibility than the object other than the warning light.

[0030] For example, in the conventional technology of Patent Document 1, warning lights lit by LED light sources are provided on the left and right of the liquid crystal display device arranged in the center. However, in the method of Patent Document 1, it is necessary to provide LED elements for the number of warning lights separately from the backlight of the liquid crystal display device, which causes problems such as increased product costs and hindered miniaturization of the device. On the other hand, in the method of driving the segment electrodes of the warning lights and the segment electrodes of the display objects other than the warning lights using the same segment drive circuit without separating the segment drive circuits as in the present embodiment, it is difficult to display the warning lights with high contrast and ensure visibility. In addition, in the method of increasing the brightness of the backlight of the liquid crystal panel 100 to improve the visibility of the warning lights, it is necessary to increase the current of the backlight to increase the brightness, which causes a problem of increasing the current consumption of the system. In addition, since the backlight illuminates the entire liquid crystal panel 100 with a uniform brightness, the warning lights and the other display objects will be displayed with the same contrast unless some ingenuity is taken. Therefore, there is a problem that the contrast cannot be increased by distinguishing only the warning lights from the other display objects in order to improve the visibility of the warning lights.

[0031] In this regard, in this embodiment, a first segment drive circuit 21 that drives the first segment electrode EL1 for displaying the warning light and a second segment drive circuit 22 that drives the second segment electrode EL2 for displaying the display object other than the warning light are separately provided. Therefore, by making the drive method of the first drive signal SG1 of the first segment drive circuit 21 different from the drive method of the second drive signal SG2 of the second segment drive circuit 22, it becomes possible to display the warning light corresponding to the first segment electrode EL1 with a higher contrast than the display object corresponding to the second segment electrode EL2. Therefore, it becomes possible to display a warning light with high visibility using the liquid crystal panel 100 without providing a separate LED light source for the warning light or unnecessarily increasing the current of the backlight.

[0032] 2.Static drive and duty drive Next, various methods for displaying a warning lamp with high contrast will be described. As shown in FIG. 4, in this embodiment, for example, the first segment drive circuit 21 drives the first segment electrode EL1 with the first drive signal SG1 of static drive, and the second segment drive circuit 22 drives the second segment electrode EL2 with the second drive signal SG2 of duty drive. By driving the first segment electrode EL1 with the first drive signal SG1 of static drive in this manner, the warning lamp corresponding to the first segment electrode EL1 can be displayed with high contrast compared to the display object corresponding to the second segment electrode EL2 driven by the second drive signal SG2 of duty drive. Therefore, it is possible to realize a driver 10 that can display a warning lamp on the liquid crystal panel 100 with high visibility.

[0033] Here, the static drive method is, for example, a method of driving each segment electrode separately. For example, when a plurality of first segment electrodes EL1 corresponding to a plurality of warning lights are provided on the liquid crystal panel 100, the first segment drive circuit 21 outputs a plurality of first drive signals SG1 to be output to the plurality of first segment electrodes EL1. For example, a plurality of segment lines connected to the plurality of first segment electrodes EL1 are wired on the liquid crystal panel 100, and each of the plurality of first drive signals SG1 from the first segment drive circuit 21 is input to each of the plurality of segment lines to drive each of the plurality of first segment electrodes EL1. According to the static drive that drives each segment electrode separately in this way, the luminance difference between when the electrode is turned on (ON display) and when it is turned off (OFF display) can be increased, so that the warning light can be displayed with high contrast.

[0034] On the other hand, the duty drive method is a dynamic drive method, specifically a drive method called a simple matrix method. In the dynamic drive method, a plurality of segment electrodes are driven by a common drive signal. For example, the second segment drive circuit 22 outputs a common second drive signal SG2 to a plurality of second segment electrodes EL2 provided in the liquid crystal panel 100 to drive them. For example, a segment line commonly connected to the plurality of second segment electrodes EL2 is wired in the liquid crystal panel 100, and the second drive signal SG2 from the second segment drive circuit 22 is input to the segment line commonly connected to the plurality of second segment electrodes EL2. The duty drive performed by the second segment drive circuit 22 includes various duty drives such as 1 / 2, 1 / 3, 1 / 4, 1 / 5, and 1 / 8. The duty drive method is, for example, a drive method using a voltage averaging method.

[0035] Fig. 5 shows an example of signal waveforms in static driving of the first segment drive circuit 21. Fig. 5 shows an example of signal waveforms when the first segment electrode EL11 to which the first drive signal SG11 and the common drive signal CM1 are applied displays black, and the first segment electrode EL12 to which the first drive signal SG12 and the common drive signal CM1 are applied displays white. Note that the following description will be given taking the normally white case as an example. Also, the reference symbols of the segment electrodes such as EL11 and EL12 will be omitted from the illustration.

[0036] The first segment drive circuit 21, which performs static drive, outputs the first drive signals SG11 and SG12 as shown in FIG. 5 to the first segment electrodes EL11 and EL12, respectively, and the first common drive circuit 31 outputs the common drive signal CM1 to the common electrodes corresponding to EL11 and EL12. As a result, a voltage signal VLC11 corresponding to the voltage difference between SG11 and CM1 is applied to the liquid crystal between the first segment electrode EL11 and the corresponding common electrode. Also, a voltage signal VLC12 corresponding to the voltage difference between SG12 and CM1 is applied to the liquid crystal between the first segment electrode EL12 and the corresponding common electrode. And since it is normally white, the voltage signal VLC11 with a high effective voltage is applied to the liquid crystal in the first segment electrode EL11, so that the warning light corresponding to the first segment electrode EL11 displays black, which indicates a lit state. On the other hand, the warning light corresponding to the first segment electrode EL12 displays white, which indicates a turned-off state.

[0037] Fig. 6 shows an example of signal waveforms of the duty drive of the second segment drive circuit 22. Fig. 6 shows an example of 1 / 4 duty drive, in which eight second segment electrodes are displayed by two segment lines corresponding to the second drive signals SG21 and SG22 and four common lines corresponding to the common drive signals CM21, CM22, CM23, and CM24. For example, in Fig. 6, one frame is divided into four subfields, and the common drive signals CM21, CM22, CM23, and CM24 are sequentially selected in each of the four subfields. Here, the upper left segment electrode driven by SG21 and CM21 is referred to as the second segment electrode EL21, and the segment electrode immediately to the right of EL21 is referred to as the second segment electrode EL22. Figure 6 shows an example of a signal waveform when the upper left second segment electrode EL21, to which the second drive signal SG21 and the common drive signal CM21 are applied, displays black, and the second segment electrode EL22 to the right of EL21, to which the second drive signal SG22 and the common drive signal CM21 are applied, displays white.

[0038] The second segment drive circuit 22, which performs duty drive, outputs second drive signals SG21 and SG22 as shown in FIG. 6 to the second segment electrodes EL21 and EL22, respectively, and the second common drive circuit 32 outputs a common drive signal CM21 to the common electrodes corresponding to EL21 and EL22. V1, V2, VC, MV1, and MV2 in FIG. 6 are drive voltages supplied by the drive voltage supply circuit 70 in FIG. 3. As a result, a voltage signal VLC21 corresponding to the voltage difference between SG21 and CM21 is applied to the liquid crystal between the second segment electrode EL21 and the corresponding common electrode. Also, a voltage signal VLC22 corresponding to the voltage difference between SG22 and CM21 is applied to the liquid crystal between the second segment electrode EL22 and the corresponding common electrode. Then, the voltage signal VLC21, which has an effective voltage higher than VLC22, is applied to the liquid crystal in the second segment electrode EL21, and the display object corresponding to the second segment electrode EL21 displays black, which indicates a lighting state. On the other hand, the display object corresponding to the second segment electrode EL22 displays white, which indicates an extinguished state.

[0039] In the static drive of Fig. 5, the effective voltage difference between the effective voltage (VLC11) applied to the liquid crystal of the first segment electrode EL11 in the on state and the effective voltage (VLC12) applied to the liquid crystal of the first segment electrode EL12 in the off state is large. On the other hand, in the duty drive of Fig. 6, the effective voltage difference between the effective voltage (VLC21) applied to the liquid crystal of the second segment electrode EL21 in the on state and the effective voltage (VLC22) applied to the liquid crystal of the second segment electrode EL22 in the off state is smaller than in the static drive of Fig. 5. Therefore, by the first segment drive circuit 21 statically driving the first segment electrodes EL11 and EL12 as shown in Fig. 5, the effective voltage difference between the on state and the off state can be made larger than in the case of the duty drive as shown in Fig. 6, and the warning lights corresponding to the first segment electrodes EL11 and EL12 can be displayed with high contrast. For example, the difference in luminance between when the liquid crystal is in a non-transmissive state and the warning light displays black, and when the liquid crystal is in a transmissive state and the warning light displays white, corresponds to the maximum luminance of the backlight, making it possible to display the warning light with high contrast. On the other hand, if the second segment electrodes EL21, EL22 of the display objects other than the warning light are driven by duty driving as shown in Fig. 6, the number of segment lines can be reduced compared to static driving, which has the advantage that the wiring area for the number of segments in the liquid crystal panel 100 can be reduced and the wiring of the segment lines can be simplified.

[0040] 4, 5, and 6, the first segment drive circuit 21 drives the first segment electrode EL1 (EL11, EL12) with the first drive signal SG1 (SG11, SG12) of static drive, and the second segment drive circuit 22 drives the second segment electrode EL2 (EL21, EL22) with the second drive signal SG2 (SG21, SG22) of duty drive. This makes it possible to display the warning light corresponding to the first segment electrode EL1 with high contrast. In addition, by duty driving the second segment electrode EL2 of the display object other than the warning light, there are advantages such as reducing the number of segment lines in the liquid crystal panel 100 and facilitating the wiring of the segment lines.

[0041] Also, in FIG. 4, the first segment drive circuit 21 outputs a first drive signal SG1 for turning on or off the warning light to the first segment electrode EL1 based on the on / off data of the warning light. For example, the data storage circuit 50 stores on / off data of the warning light, and this on / off data is read from the data storage circuit 50 and input to the first segment drive circuit 21 via, for example, the data latch 41. Then, when the on / off data of the warning light indicates an on display, the first segment drive circuit 21 outputs a first drive signal SG1 for turning on the warning light to the first segment electrode EL1. For example, the first segment drive circuit 21 outputs a first drive signal SG11 as shown in FIG. 5 to the first segment electrode EL11. On the other hand, when the on / off data of the warning light indicates an off display, the first drive signal SG1 for turning off the warning light to the first segment electrode EL1. For example, the first segment drive circuit 21 outputs a first drive signal SG12 as shown in FIG. 5 to the first segment electrode EL12. In this way, the first segment drive circuit 21 can output the first drive signal SG1 that turns the warning light on or off to the first segment electrode EL1 based on the on / off data of the warning light. And because the first segment drive circuit 21 outputs the first drive signal SG1 for static drive, it is possible to increase the difference between the effective voltage of the liquid crystal when the warning light is turned on by the on / off data and the effective voltage of the liquid crystal when the warning light is turned off, and it becomes possible to display the warning light with high contrast.

[0042] As shown in Fig. 3, the driver 10 of this embodiment includes a first common drive circuit 31 that drives the first common electrode corresponding to the first segment electrode EL1 and a second common drive circuit 32 that drives the second common electrode corresponding to the second segment electrode EL2. In this way, even if the drive method of the first segment electrode EL1 and the drive method of the second segment electrode EL2 are different, such as the static drive method and the duty drive method, as described above, the first common drive circuit 31 and the second common drive circuit 32 can output common drive signals CM1 and CM2 appropriate for each drive method. Therefore, by making the drive methods of the first segment electrode EL1 and the second segment electrode EL2 different, it is possible to display the warning light corresponding to the first segment electrode EL1 with high contrast, while driving the first common electrode and the second common electrode with appropriate common drive signals according to each drive method.

[0043] 3.Static drive by PWM, PAM In Fig. 7, the first segment drive circuit 21 drives the first segment electrode EL1 with a first drive signal SG1 for static drive, and the second segment drive circuit 22 drives the second segment electrode EL2 with a second drive signal SG2 for static drive. That is, while the first segment drive circuit 21 performs static drive and the second segment drive circuit 22 performs duty drive in Fig. 4, both the first segment drive circuit 21 and the second segment drive circuit 22 perform static drive in Fig. 7.

[0044] 7, the first segment drive circuit 21 outputs a first drive signal SG1 for turning on or off the warning light to the first segment electrode EL1 based on the on / off data of the warning light. For example, the on / off data of the warning light is read from the data storage circuit 50 and input to the first segment drive circuit 21 via the data latch 41. When the on / off data of the warning light indicates an on display, the first segment drive circuit 21 outputs a first drive signal SG1 for turning on the warning light to the first segment electrode EL1. When the on / off data of the warning light indicates an off display, the first segment drive circuit 21 outputs a first drive signal SG1 for turning off the warning light to the first segment electrode EL1.

[0045] On the other hand, the second segment drive circuit 22 outputs a second drive signal SG2 for displaying the display object in a gradation to the second segment electrode EL2 based on the gradation data of the display object. For example, the gradation data of the display object is read from the data storage circuit 50 and input to the second segment drive circuit 22 via the data latch 42. Then, the second segment drive circuit 22 outputs a second drive signal SG2 according to the gradation data to the second segment electrode EL2 to perform gradation display of the display object corresponding to the second segment electrode EL2. For example, the second segment drive circuit 22 performs gradation display of the display object corresponding to the second segment electrode EL2 by generating a PWM signal or a PAM signal based on the gradation data. In this way, for a warning light, the first segment electrode EL1 is statically driven by the first drive signal SG1 based on the on / off data of the warning light, so that the warning light can be displayed with high contrast. On the other hand, for a display object other than a warning light, the second segment electrode EL2 is statically driven by the second drive signal SG2 based on the gradation data, so that the display object can be displayed in a gradation.

[0046] For example, the second segment drive circuit 22 performs gradation display of the display object displayed by the second segment electrode EL2 by the second drive signal SG2, which is a PWM signal. For example, the second segment drive circuit 22 outputs the second drive signal SG2, which is a PWM signal whose pulse width (duty ratio) changes according to the gradation data, to the second segment electrode EL2, thereby realizing the gradation display of the display object. In this way, for the warning light, the warning light can be displayed with high contrast by static driving based on the on / off data of the warning light, and for the display objects other than the warning light, the gradation display of the display object can be realized by static driving by the PWM signal based on the gradation data.

[0047] FIG. 8 shows an example of a signal waveform of static drive by a PWM signal. The first segment drive circuit 21 outputs a first drive signal SG1 with a pulse width PW1 as shown in FIG. 8 to the first segment electrode EL1 based on the on / off data of the warning light. The first common drive circuit 31 outputs a common drive signal CM1 as shown in FIG. 8. The first drive signal SG1 in FIG. 8 is a signal waveform when the on / off data of the warning light indicates an on display and the warning light is turned on. As a result, a voltage signal VLC1 corresponding to the voltage difference between the first drive signal SG1 and the common drive signal CM1 is applied to the liquid crystal between the first segment electrode EL1 and the corresponding common electrode. The effective voltage applied to the liquid crystal by this voltage signal VLC1 is large, so that the warning light can be displayed with high contrast.

[0048] On the other hand, the second segment driving circuit 22 outputs a second driving signal SG2 with a pulse width PW2 as shown in FIG. 8 to the second segment electrode EL2 based on the grayscale data of the display object. The second common driving circuit 32 outputs a common driving signal CM2 as shown in FIG. 8. The length of the pulse width PW2 of the second driving signal SG2 in FIG. 8 is set according to the grayscale data. For example, when the grayscale value of the grayscale data is high, the pulse width PW2 becomes longer, and when the grayscale value of the grayscale data is low, the pulse width PW2 becomes shorter, so that the second driving signal SG2 is PWM-modulated. In terms of duty ratio, for example, PWM modulation is performed such that the duty ratio changes in the range of 0 to X%. As a result, a voltage signal VLC2 corresponding to the voltage difference between the second driving signal SG2 and the common driving signal CM2 is applied to the liquid crystal between the second segment electrode EL2 and the corresponding common electrode. The effective voltage of this voltage signal VLC2 changes according to the length of the pulse width PW2, so that grayscale display of the display object based on the grayscale data is possible. That is, the duty ratio of the second drive signal SG2 is set based on the grayscale data, thereby enabling grayscale display of the displayed object.

[0049] The pulse width PW1 of the first drive signal SG1 is longer than the pulse width PW2 of the second drive signal SG2, which is a PWM signal. For example, the pulse width PW2 is variably set according to the grayscale data, and the pulse width PW1 of the first drive signal SG1 is longer than the pulse width PW2 of the second drive signal SG2, which is variably set in this manner. For example, the duty ratio of the first drive signal SG1 is greater than X%. Therefore, the effective voltage applied to the liquid crystal of the first segment electrode EL1 is greater than the effective voltage applied to the liquid crystal of the second segment electrode EL2, so that the warning light corresponding to the first segment electrode EL1 can be displayed with a higher contrast than the display object corresponding to the second segment electrode EL2. Note that a modification in which the duty ratio of the first drive signal SG1 is set to X% is also possible.

[0050] Alternatively, the second segment drive circuit 22 performs gradation display of the display object displayed by the second segment electrode EL2 by the second drive signal SG2 of a PAM signal. For example, the second segment drive circuit 22 outputs the second drive signal SG2 of a PAM signal whose voltage amplitude changes according to gradation data to the second segment electrode EL2, thereby realizing gradation display of the display object. In this way, for the warning light, the warning light can be displayed with high contrast by static driving based on the on / off data of the warning light, and for the display objects other than the warning light, the gradation display of the display objects can be realized by static driving by the PAM signal based on the gradation data.

[0051] FIG. 9 shows an example of a signal waveform of static drive by a PAM signal. The first segment drive circuit 21 outputs a first drive signal SG1 with a voltage amplitude AM1 as shown in FIG. 9 to the first segment electrode EL1 based on the on / off data of the warning light. The first common drive circuit 31 outputs a common drive signal CM1 as shown in FIG. 9. The first drive signal SG1 in FIG. 9 is a signal waveform when the on / off data of the warning light indicates an on display and the warning light is turned on. As a result, a voltage signal VLC1 corresponding to the voltage difference between the first drive signal SG1 and the common drive signal CM1 is applied to the liquid crystal between the first segment electrode EL1 and the corresponding common electrode. The effective voltage applied to the liquid crystal by this voltage signal VLC1 is large, so that the warning light can be displayed with high contrast.

[0052] On the other hand, the second segment driving circuit 22 outputs the second driving signal SG2 with the voltage amplitude AM2 as shown in FIG. 9 to the second segment electrode EL2 based on the grayscale data of the display object. The second common driving circuit 32 outputs the common driving signal CM2 as shown in FIG. 9. The magnitude of the voltage amplitude AM2 of the second driving signal SG2 in FIG. 9 is set according to the grayscale data. For example, when the grayscale value of the grayscale data is high, the voltage amplitude AM2 becomes large, and when the grayscale value of the grayscale data is low, the voltage amplitude AM2 becomes small, so that the PAM of the second driving signal SG2 is modulated. As a result, a voltage signal VLC2 corresponding to the voltage difference between the second driving signal SG2 and the common driving signal CM2 is applied to the liquid crystal between the second segment electrode EL2 and the corresponding common electrode. The effective voltage of this voltage signal VLC2 changes according to the magnitude of the voltage amplitude AM2, so that grayscale display of the display object based on the grayscale data is possible.

[0053] The voltage amplitude AM1 of the first drive signal SG1 is larger than the voltage amplitude AM2 of the second drive signal SG2, which is a PAM signal. For example, the voltage amplitude AM1 is variably set according to the gradation data, and the voltage amplitude AM1 of the first drive signal SG1 is larger than the voltage amplitude AM2 of the second drive signal SG2, which is variably set in this manner. Therefore, the effective voltage applied to the liquid crystal of the first segment electrode EL1 is larger than the effective voltage applied to the liquid crystal of the second segment electrode EL2, so that the warning light corresponding to the first segment electrode EL1 can be displayed with a higher contrast than the display object corresponding to the second segment electrode EL2. It is not necessary to display all display objects other than the warning light in gradation using PWM signals or PAM signals, and some display objects other than the warning light may have a fixed pulse width or voltage amplitude, or may only be displayed on and off.

[0054] In addition, when displaying objects other than warning lights in gradation by PWM signals, as shown in FIG. 10, the voltage amplitude AM1 of the first drive signal SG1 may be made larger than the voltage amplitude AM2 of the PWM signal, which is the second drive signal SG2. For example, in FIG. 10, the second drive signal SG2 for driving the second segment electrode EL2 is a PWM signal whose pulse width PW2 changes based on the gradation data. The voltage amplitude AM1 of the first drive signal SG1 for driving the first segment electrode EL1 of the warning light is larger than the voltage amplitude AM2 of the second drive signal SG2, which is a PWM signal. The pulse width PW1 of the first drive signal SG1 is longer than the pulse width PW2 of the second drive signal SG2, which is a PWM signal. In this way, the effective voltage of the voltage signal VLC1 applied to the liquid crystal of the first segment electrode EL1 can be made even larger than the effective voltage of the voltage signal VLC1 in FIG. 8, which was described as normal PWM drive. Therefore, the warning light corresponding to the first segment electrode EL1 can be displayed with higher contrast.

[0055] As shown in FIG. 3, the driver 10 of this embodiment includes a data storage circuit 50 that stores on / off data of a warning light for generating the first drive signal SG1 and gradation data of a display object for generating the second drive signal SG2. For example, the interface circuit 80 receives the on / off data of the warning light and the gradation data of the display object from the processing device 300, and the control circuit 60 writes the received on / off data of the warning light and the gradation data of the display object into the data storage circuit 50, which is a RAM. Then, the on / off data of the warning light from the data storage circuit 50 is input to the first segment drive circuit 21 via the data latch 41, and the gradation data of the display object from the data storage circuit 50 is input to the second segment drive circuit 22 via the data latch 42. Then, when the on / off data indicates an on display, the first segment drive circuit 21 outputs the first drive signal SG11 as shown in FIG. 5, or outputs the first drive signal SG1 as shown in FIG. 8, FIG. 9, and FIG. 10. Furthermore, when the on / off data indicates an off display, the first segment drive circuit 21 outputs a first drive signal SG12 as shown in Fig. 5. Furthermore, the second segment drive circuit 22 outputs second drive signals SG21 and SG22 as shown in Fig. 6 based on the gradation data of the display object, or outputs a second drive signal SG2 as shown in Fig. 8, Fig. 9, and Fig. 10. In this manner, it becomes possible to display the warning light with high contrast based on the on / off data of the warning light stored in the data storage circuit 50, and it becomes possible to perform gradation display of the display object based on the gradation data of the display object stored in the data storage circuit 50.

[0056] As shown in FIG. 3, the driver 10 has a first terminal TS1 to which the first drive signal SG1 is output and which is connected to the first segment electrode EL1 of the liquid crystal panel 100, and a second terminal TS2 to which the second drive signal SG2 is output and which is connected to the second segment electrode EL2 of the liquid crystal panel 100. The first terminal TS1 and the second terminal TS2 are, for example, pads of the driver 10. For example, the first terminal TS1 is connected to the first segment electrode EL1 via a connection wiring or a segment line of the liquid crystal panel 100, and the second terminal TS2 is connected to the second segment electrode EL2 via a connection wiring or a segment line of the liquid crystal panel 100. These first terminal TS1 and second terminal TS2 are arranged, for example, along the long side of the driver 10 in a plan view. If such a first terminal TS1 is provided, the first drive signal SG1 from the first segment drive circuit 21 can be input to the first segment electrode EL1 via the first terminal TS1, and the warning light corresponding to the first segment electrode EL1 can be driven with high contrast. Furthermore, a second drive signal SG2 from the second segment drive circuit 22 is input to the second segment electrode EL2 via the second terminal TS2, enabling gradation display or the like of an object corresponding to the second segment electrode EL2.

[0057] 4. Layout and backlight FIG. 11 shows an example of the layout arrangement of the first segment drive circuit 21 and the second segment drive circuit 22 in the driver 10. In FIG. 11, the driver 10, which is a semiconductor IC, has short sides SD1 and SD2 and long sides SD3 and SD4 in a plan view. Side SD2 is the opposite side to side SD1, and side SD4 is the opposite side to side SD3. The direction along the long sides SD4 and SD3 is the first direction DR1, and the direction perpendicular to the first direction DR1 is the second direction DR2. The second direction DR2 is the direction along the short sides SD1 and SD2. For example, the first direction DR1 is the direction from side SD1 to side SD2, which is the opposite side to side SD1. The second direction DR2 is the direction from side SD3 to side SD4, which is the opposite side to side SD3. The shape of the driver 10 in a plan view may be a substantially quadrilateral, and may have chamfered portions, for example, at the corners of the quadrilateral.

[0058] In this way, when the long side direction of the driver 10 is the first direction DR1, the first segment drive circuit 21 and the second segment drive circuit 22 are arranged along the first direction DR1. For example, in FIG. 11, the first segment drive circuit 21 and the second segment drive circuit 22 are arranged adjacent to each other along the first direction DR1. In this way, the first segment drive circuit 21 is arranged in a first region along the long side direction of the driver 10, and the second segment drive circuit 22 is arranged in a second region along the long side direction of the driver 10. As a result, the first segment drive circuit 21 for the warning light and the second segment drive circuit 22 for the display object other than the warning light are arranged in separate regions such as the first region and the second region, and the first segment drive circuit 21 enables high-contrast display of the warning light, while the second segment drive circuit 22 enables gradation display of the display object other than the warning light.

[0059] Also, in Fig. 12, a plurality of first segment drive circuits 21, 23 and a plurality of second segment drive circuits 22, 24 are provided. In Fig. 12, the first segment drive circuit 21 and the second segment drive circuit 22 are arranged along the first direction DR1, and the first segment drive circuit 23 and the second segment drive circuit 24 are arranged along the first direction DR1. Note that Fig. 12 shows a case where two first segment drive circuits 21, 23 and two second segment drive circuits 22, 24 are provided, but three or more first segment drive circuits or three or more second segment drive circuits may be provided.

[0060] At least one of the first common drive circuit 31 and the second common drive circuit 32 described in Fig. 3 may be disposed between the first segment drive circuit 21 and the second segment drive circuit 22, between the first segment drive circuit 23 and the second segment drive circuit 24, or between the first segment drive circuit 21 and the second segment drive circuit 24. Also, by controlling the control circuit 60 in Fig. 3, each terminal of the driver 10 may be switched to be connected to the first segment drive circuit or the second segment drive circuit. For example, when the external processing device 300 issues a command for setting the terminals to be switched, the control circuit 60 may switch whether each terminal of the driver 10 is connected to the first segment drive circuit or the second segment drive circuit based on this command.

[0061] As shown in FIG. 1 and FIG. 3, the electro-optical device 200 of this embodiment includes a driver 10 and a liquid crystal panel 100. This allows the liquid crystal panel 100 to display a warning light with high contrast while also displaying objects other than the warning light. As shown in FIG. 13, the electro-optical device 200 includes a backlight 110. In FIG. 13, the backlight 110 includes a light guide plate 130 and a light source 120 provided on at least one side of the light guide plate 130. The light source 120 is realized by, for example, an LED element or a cold cathode fluorescent lamp. For example, a backlight of a type called an edge light type or a side light type can be used as the backlight 110. Although FIG. 13 shows a side view of the electro-optical device 200, the light source 120 is provided on, for example, one side of the light guide plate 130 in a plan view of the electro-optical device 200. In this case, a plurality of light sources 120 may be arranged on one side of the light guide plate 130. Alternatively, the light source 120 may be provided on a first side of the light guide plate 130, and the light source 120 may be provided on a second side opposite to the first side of the light guide plate 130. The light guide plate 130, which is a light guide sheet, is realized by, for example, an acrylic plate. Between the light guide plate 130 and the liquid crystal panel 100, a diffusion plate 134, which is, for example, a diffusion sheet, is provided. In addition, a reflection plate 132, which is, for example, a reflection sheet, is provided on the surface of the light guide plate 130 opposite the liquid crystal panel 100. By providing a backlight 110 as shown in FIG. 13, the light from the light source 120 is guided by the light guide plate 130, and the guided light can be substantially uniformly incident on the liquid crystal panel 100 from the rear side of the liquid crystal panel 100.

[0062] 13, the light from the backlight 110 is irradiated almost uniformly from the rear side of the liquid crystal panel 100, making it difficult to display the warning light with high contrast by controlling the backlight 110. In this regard, in this embodiment, a first segment drive circuit 21 dedicated to the warning light is provided, and the drive method of the first drive signal SG1 from this first segment drive circuit 21 is devised to drive the first segment electrode EL1 corresponding to the warning light. In this way, even when the backlight 110 of the type shown in FIG. 13 is used, it is possible to provide an electro-optical device 200 that can display the warning light with a higher contrast than other displayed objects.

[0063] As described above, the driver of this embodiment is a driver for driving a group of segment electrodes of a liquid crystal panel, and includes a first segment drive circuit for driving a first segment electrode for displaying a warning light among the group of segment electrodes, and a second segment drive circuit for driving a second segment electrode for displaying an object other than the warning light among the group of segment electrodes. The first segment drive circuit outputs a first drive signal that displays the warning light displayed by the first segment electrode with a higher contrast than the object displayed by the second segment electrode driven by the second drive signal of the second segment drive circuit.

[0064] According to this embodiment, a first segment drive circuit for driving a first segment electrode for displaying a warning light and a second segment drive circuit for driving a second segment electrode for displaying a display object other than the warning light are separately provided. By providing a first segment drive circuit for the warning light in this manner, the first drive signal of the first segment drive circuit makes it possible to display the warning light with a higher contrast than the display object other than the warning light. This makes it possible to ensure the visibility of the warning light even when the warning light is displayed using a liquid crystal panel. Therefore, it is possible to provide a driver or the like who can display display objects other than the warning light on the liquid crystal panel and can display the warning light on the liquid crystal panel with higher visibility than the display object.

[0065] In addition, in this embodiment, the first segment drive circuit may drive the first segment electrodes with a first drive signal for static drive, and the second segment drive circuit may drive the second segment electrodes with a second drive signal for duty drive.

[0066] By driving the first segment electrode with the first drive signal of static drive in this manner, the warning light corresponding to the first segment electrode can be displayed with higher contrast than the display object corresponding to the second segment electrode driven by the second drive signal of duty drive.

[0067] In this embodiment, the first segment drive circuit may output a first drive signal for turning on or off the warning light to the first segment electrode based on on / off data for the warning light.

[0068] In this way, the first segment drive circuit can output a first drive signal to the first segment electrode to turn on or off the warning light based on the on / off data of the warning light. Since the first segment drive circuit outputs a first drive signal for static drive, the warning light can be displayed with high contrast.

[0069] Furthermore, this embodiment may include a first common drive circuit that drives a first common electrode corresponding to the first segment electrode, and a second common drive circuit that drives a second common electrode corresponding to the second segment electrode.

[0070] In this way, even if the drive method for the first segment electrode and the drive method for the second segment electrode are different, the first common drive circuit and the second common drive circuit can output common drive signals appropriate for each drive method.

[0071] The first segment drive circuit may drive the first segment electrodes with a first drive signal for static drive, and the second segment drive circuit may drive the second segment electrodes with a second drive signal for static drive. The first segment drive circuit may output a first drive signal for turning on or off a warning light to the first segment electrodes based on on / off data for the warning light, and the second segment drive circuit may output a second drive signal for displaying a display object in gradations to the second segment electrodes based on gradation data for the display object.

[0072] In this way, the first segment electrodes are statically driven by the first drive signal based on the on / off data of the warning light, thereby enabling the warning light to be displayed with high contrast, while the second segment electrodes are statically driven by the second drive signal based on the gradation data, enabling the display object other than the warning light to be displayed in gradations.

[0073] The second segment drive circuit may perform gradation display of an object displayed by the second segment electrodes in response to a second drive signal that is a PWM signal.

[0074] In this way, the warning light can be displayed with high contrast by static driving based on the on / off data of the warning light, and gradation display of displayed objects other than the warning light can be achieved by static driving using a PWM signal based on the gradation data.

[0075] Furthermore, in this embodiment, the voltage amplitude of the first drive signal may be greater than the voltage amplitude of the PWM signal.

[0076] In this way, the effective voltage applied to the liquid crystal of the first segment electrode can be further increased, so that the warning light corresponding to the first segment electrode can be displayed with higher contrast.

[0077] In this embodiment, the second segment drive circuit may perform gradation display of an object displayed by the second segment electrodes in response to the second drive signal, which is a PAM signal.

[0078] In this way, the warning light can be displayed with high contrast by static driving based on the on / off data of the warning light, and gradation display of displayed objects other than the warning light can be achieved by static driving using a PAM signal based on the gradation data.

[0079] In this embodiment, a data storage circuit may be included that stores warning light on / off data for generating the first drive signal and display object grayscale data for generating the second drive signal.

[0080] In this way, the warning light can be displayed with high contrast based on the on / off data of the warning light stored in the data storage circuit, and the displayed object can be displayed in gradation based on the gradation data of the displayed object stored in the data storage circuit.

[0081] In addition, this embodiment may include a first terminal to which the first drive signal is output and which is connected to a first segment electrode of the liquid crystal panel, and a second terminal to which the second drive signal is output and which is connected to a second segment electrode of the liquid crystal panel.

[0082] In this way, a first drive signal from a first segment drive circuit can be input to a first segment electrode via a first terminal to drive a warning light corresponding to the first segment electrode with high contrast, and a second drive signal from a second segment drive circuit can be input to a second segment electrode via a second terminal to display an object corresponding to the second segment electrode.

[0083] In this embodiment, when the long side direction of the driver is defined as a first direction, the first segment drive circuit and the second segment drive circuit may be arranged along the first direction.

[0084] In this way, a first segment drive circuit for the warning light and a second segment drive circuit for displays other than the warning light are arranged in separate areas, allowing the first segment drive circuit to display the warning light in high contrast while the second segment drive circuit allows the display of displays other than the warning light.

[0085] The present embodiment also relates to an electro-optical device including the driver described above and a liquid crystal panel.

[0086] According to such an electro-optical device, it is possible to display a warning light with high contrast on the liquid crystal panel while also displaying other display items besides the warning light.

[0087] In addition, this embodiment may include a backlight including a light guide plate and a light source provided on at least one side of the light guide plate.

[0088] By providing such a backlight, light from the light source is guided by the light guide plate, and the guided light can be made to enter the liquid crystal panel from the rear side of the liquid crystal panel approximately uniformly.

[0089] Although the present embodiment has been described in detail as above, it will be easily understood by those skilled in the art that many modifications are possible without substantially departing from the novel matters and effects of the present disclosure. Therefore, all such modifications are intended to be included in the scope of the present disclosure. For example, a term described at least once in the specification or drawings together with a different term having a broader meaning or synonymy can be replaced with that different term anywhere in the specification or drawings. In addition, all combinations of the present embodiment and modifications are also included in the scope of the present disclosure. In addition, the configurations and operations of the driver, electro-optical device, liquid crystal panel, etc. are not limited to those described in the present embodiment, and various modifications are possible. [Explanation of symbols]

[0090] 10...driver, 21, 23...first segment drive circuit, 22, 24...second segment drive circuit, 31...first common drive circuit, 32...second common drive circuit, 40...control circuit, 41, 42...data latch, 50...data storage circuit, 60...control circuit, 70...drive voltage supply circuit, 80...interface circuit, 100...liquid crystal panel, 110...backlight, 120...light source, 130...light guide plate, 132...reflector, 134...diffuser, 200...electro-optical device, 300...processing device, CM 1, CM2, CM21, CM22, CM23, CM24...common drive signal, DR1...first direction, DR2...second direction, EL1, EL11, EL12...first segment electrode, EL2, EL21, EL22...second segment electrode, SG1, SG11, SG12...first drive signal, SG2, SG21, SG22...second drive signal, TM1, TM2...common terminal, TS1...first terminal, TS2...second terminal, VLC1, VLC11, VLC12, VLC2, VLC21, VLC22...voltage signal

Claims

1. A driver for driving a segment electrode group of a liquid crystal panel, a first segment driving circuit for driving a first segment electrode for displaying a warning light among the group of segment electrodes; a second segment drive circuit for driving a second segment electrode of the group of segment electrodes for displaying an indication other than the warning light; Including, The first segment driving circuit includes: A driver that outputs a first drive signal that displays the warning light displayed by the first segment electrode with higher contrast than the display object displayed by the second segment electrode driven by the second drive signal of the second segment drive circuit.

2. 2. The driver according to claim 1, The first segment driving circuit includes: driving the first segment electrode by the first drive signal of static drive; The second segment drive circuit includes: a driver for driving the second segment electrodes by the second drive signal of duty drive;

3. 3. The driver according to claim 2, The first segment driving circuit includes: a driver that outputs the first drive signal for turning on or off the warning light to the first segment electrode based on on / off data of the warning light.

4. 2. The driver according to claim 1, a first common driving circuit for driving a first common electrode corresponding to the first segment electrode; a second common driving circuit for driving a second common electrode corresponding to the second segment electrode; A driver comprising:

5. 2. The driver according to claim 1, The first segment driving circuit includes: driving the first segment electrode by the first drive signal of static drive; The second segment drive circuit includes: driving the second segment electrode by the second drive signal of static drive; The first segment driving circuit includes: outputting the first drive signal for turning on or off the warning light to the first segment electrode based on on / off data of the warning light; The second segment drive circuit includes: a driver for outputting, to the second segment electrodes, the second drive signal for displaying the object in gradation based on gradation data of the object;

6. 6. The driver according to claim 5, The second segment drive circuit includes: a driver for performing gradation display of the display object displayed by the second segment electrodes in response to the second drive signal which is a PWM signal;

7. 7. The driver according to claim 6, A driver, wherein the voltage amplitude of the first drive signal is greater than the voltage amplitude of the PWM signal.

8. 6. The driver according to claim 5, The second segment drive circuit includes: a driver for performing gradation display of the display object displayed by the second segment electrodes in response to the second drive signal which is a PAM signal.

9. 2. The driver according to claim 1, A driver comprising: a data storage circuit that stores on / off data of the warning light for generating the first drive signal, and gradation data of the display object for generating the second drive signal.

10. 2. The driver according to claim 1, a first terminal to which the first driving signal is output and which is connected to the first segment electrode of the liquid crystal panel; a second terminal to which the second driving signal is output and which is connected to the second segment electrode of the liquid crystal panel; A driver comprising:

11. 2. The driver according to claim 1, When the long side direction of the driver is the first direction, A driver, characterized in that the first segment driving circuit and the second segment driving circuit are arranged along the first direction.

12. A driver according to any one of claims 1 to 11; The liquid crystal panel; 1. An electro-optical device comprising:

13. 13. The electro-optical device according to claim 12, 1. An electro-optical device comprising: a backlight including a light guide plate and a light source provided on at least one side of the light guide plate.

Images