JP2007148204A - Liquid crystal display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display apparatus eliminating non-display of a screen after turning on a power supply. <P>SOLUTION: The liquid crystal display apparatus is provided with: a detection part 13 for detecting the existence of an external synchronizing signal 19; a storage part 7; a switching part 14 for inputting internal image data 43 stored in the storage part 7, inputting external image data 18 and inputting a first selection signal 20; a liquid crystal panel 11; a signal drive part 9 and a scanning drive part 10 for driving the liquid crystal panel 11; and a timing control part 16 for outputting at least respective timing signals to respective driving parts 9, 10. When the detection part 13 detects the absence of the external synchronizing signal 19, the switching part 14 outputs the internal image data 43 or set picture data 43A to the timing control part 16 in accordance with the selection state of the first selection signal 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device.

Conventionally, this type of apparatus is shown, for example, in FIG. According to FIG. 1, the input means 3 is connected to an external device, and external synchronization signals HD, VD and external image data R, G, B are input. External image data R, G, and B are input to the liquid crystal panel 17 via the scaler 11 and the transmitter 16.
JP 2004-252234 A

When the external device is, for example, an in-vehicle navigation main body, after the power is turned on (for example, a car key is turned or the user presses the power switch of the main body), it takes several seconds for the liquid crystal display device to display the screen. There are drawbacks. This is because the external image data is output to the liquid crystal display device after the main body prepares various data (for example, temperature oil amount, self-diagnosis, etc.).

  For this reason, the user does not display the screen even when the power is turned on. Accordingly, the present invention provides a liquid crystal display device that eliminates the non-display of the screen after the power is turned on in consideration of such conventional drawbacks.

  In order to solve the above problem, in the present invention of claim 1, a detection unit for detecting the presence or absence of an external synchronization signal, a storage unit, internal image data in the storage unit is input, external image data is input, And a switching unit to which the first selection signal is input, a liquid crystal panel, a signal driving unit and a scanning driving unit that drive the liquid crystal panel, and a timing control unit that outputs at least each timing signal to each driving unit. And when the detection unit detects that there is no external synchronization signal, the switching unit sends the internal image data or setting screen data to the timing control unit according to a selection state of the first selection signal. Output.

  In the present invention of claim 2, when the first selection signal is selected to the first state, the switching unit outputs the internal image data for displaying a logo.

  In the present invention of claim 3, when the first selection signal is selected to the second state, the switching unit converts the internal image data into setting screen data and outputs the setting screen data.

  In this invention of Claim 4, an image generation part is provided between the said memory | storage part and the said switch part, and the said image generation part has a color palette.

  In the present invention of claim 5, a second selection signal is input to the switching unit, and the switching unit receives predetermined color data from the internal image data according to a selection state of the second selection signal. By selecting, the setting screen data is generated.

  According to the configuration of the first aspect, when there is no external synchronization signal, the internal image data or the setting screen data is output according to the selection state of the first selection signal, so that the screen is displayed immediately after the power is turned on.

  As in claim 2, when the first selection signal is selected to the first state, a logo is displayed immediately after the power is turned on. In this way, a user who prefers to display a logo only needs to select the first state, and can select a screen according to the user's preference.

  As in the third aspect, when the first selection signal is selected to the second state, the setting screen is displayed immediately after the power is turned on. Thus, the user who likes the setting screen may select the second state, and can select a screen according to the user's preference.

  According to the fourth aspect of the present invention, since the image generation unit has a color palette, the capacity of the storage unit can be reduced, and an inexpensive storage unit can be used.

  As in the fifth aspect, since predetermined color data can be selected according to the selection state of the second selection signal, a setting screen for displaying a color according to the user's preference can be selected.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below in detail with reference to embodiments and the drawings. The embodiments described below exemplify liquid crystal display devices for embodying the technical idea of the present invention. However, the present invention is not intended to be specified in this embodiment, and the present invention is equally applicable to various modifications without departing from the technical concept shown in the claims. It can be applied.

  Hereinafter, a liquid crystal display device 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram showing a liquid crystal display device 1, and FIG. 2 is a block diagram of an integrated circuit used in the liquid crystal display device 1.

  In FIG. 1, the liquid crystal display device 1 includes, for example, a connector 2, a bus 3, an internal power supply unit 4, an integrated circuit 5, a transmitter 6, a storage unit 7, a timing controller 8, and a signal drive unit 9. The scanning drive unit 10 and the liquid crystal panel 11 are included.

  The integrated circuit 5 includes an image generation unit 12, a detection unit 13, a switching unit 14, and the like. The timing controller 8 includes a gamma circuit 15 and a timing control unit 16.

  The in-vehicle navigation main body includes an external power supply unit 17, a data source, a synchronization signal source, an input unit (both not shown), and the like. Outputs 3 volts.

  The data source outputs external image data 18 to the connector 2. The synchronization signal source outputs an external synchronization signal 19 to the connector 2. The input unit outputs a first selection signal 20 and a second selection signal 21 to the connector 2 (see FIG. 2).

  On the input side of the internal power supply unit 4, 3.3 VDC is input from the external power supply unit 17 through the connector 2. The output side of the internal power supply unit 17 outputs, for example, DC-15 volts, 0 volts, 3.3 volts, 5 volts, and 15 volts.

  The direct current 3.3 volts is supplied to, for example, the detection unit 13, the switching unit 14, the transmitter 6, the image generation unit 12, the storage unit 7, the timing control unit 16, and the logic unit of the signal driving unit 9. Supplied. DC-15 volts and 15 volts are supplied as drive voltages for the scanning drive unit 10. The DC 5 volts is supplied to the logic unit of the scan driving unit 10.

  Between the connector 2 and the gamma circuit 15, a bus 3, a microcomputer 22, a DA converter 23, and the like are provided (see FIG. 2). The gamma circuit 15 includes, for example, a plurality of switches.

  The microcomputer 22 outputs a plurality of serial data to the DA converter 23. The DA converter 23 converts each serial data into a plurality of reference voltages (analog values).

  The gamma circuit 15 switches the plurality of reference voltages to a plurality of gradation reference voltages 24. The gamma circuit 15 outputs a plurality of gradation reference voltages to the voltage dividing circuit in the signal driver 9. The voltage dividing circuit outputs a plurality of gradation reference voltages to a DA converter (not shown) in the signal driver 9.

  On the other hand, the timing controller 16 outputs image data 25 (digital value) to the DA converter in the signal driver 9.

  As a result, the DA converter outputs a gradation voltage 26 (R, G, B analog values) corresponding to the image data 25 to the liquid crystal panel 11. In this way, gradation control is performed.

  As shown in FIG. 2, the internal synchronization signal generation unit 27 includes a horizontal counter 28, a decoder 29, a vertical counter 30, a decoder 30, and a decoder 31. An internal dot clock is input from the transmitter 6 to the horizontal counter 28. The horizontal counter 28 and the decoder 29 are connected.

  The decoder 29 and the vertical counter 30 are connected. The vertical counter 30 and the decoder 31 are connected.

  The decoder 29 receives the H size signal. The H size signal is a signal indicating a value obtained by adding a margin to the number of pixels in the horizontal direction in the liquid crystal panel 11.

  The decoder 31 receives a V size signal. The V size signal is a signal indicating a value obtained by adding a margin to the number of pixels in the vertical direction in the liquid crystal panel 11.

  With the above configuration, the decoder 29 outputs the internal horizontal synchronization signal (horizontal) 33H and the data enable signal 34. The decoder 31 outputs an internal synchronization signal (vertical) 33V. These signals 33H, 33V, and 34 constitute an internal synchronization signal 33.

  In FIG. 2, the detection unit 13 includes a shift register 35 and a detector 36. The shift register 35 receives an internal synchronization signal (vertical) 33V and an external synchronization signal (vertical) 19V.

  The detection unit 13 detects the presence or absence of the external synchronization signal 19. When detecting the absence of the external synchronization signal 19, the detection unit 13 outputs a low state detection signal 37 to the first selection unit 38 of the switching unit 14.

  The image generation unit 12 includes an internal synchronization signal generation unit 27, an interface circuit 39, and a color selection unit 40.

  The storage unit 7 is composed of, for example, a flash ROM. The image generation unit 12 outputs a control signal 41 (a signal for performing a read command) and an address signal 42 to the storage unit 7.

  As a result, the storage unit 7 outputs the stored internal image data 43 (for example, data for displaying a logo of a specific company) to the image generation unit 12. Then, the image generation unit 12 outputs internal image data 43 to the switching unit 14 (see FIGS. 1 and 2).

  As shown in FIG. 2, the switching unit 14 includes a first selection unit 38 and a second selection unit 44, and both are connected.

  An external dot clock 45, an external synchronization signal 9, and external image data 18 are input to the first selection unit 38. Further, the internal dot clock 32, the internal synchronization signal 33, the internal image data 43, and the detection signal 37 are input to the first selection unit 38.

  When the detection unit 13 detects that the external synchronization signal 19 (specifically, the external synchronization signal (vertical) 19V) is not present, the detection signal 37 is in a low state. At this time, the first selection unit 38 outputs the internal synchronization signal 33 and the clock signal 46.

  At this time, the internal image data 43, the first selection signal 20, and the second selection signal 21 are input to the second selection unit 44. The first selection signal 20 has priority over the second selection signal 21.

  That is, when the first selection signal 20 is selected to the first state (for example, the high state), the second selection unit 44 validates the internal image data 43 and outputs the internal image data 43.

  When the first selection signal 20 is selected to the second state (for example, the low state), the second selection unit 44 invalidates the internal image data 43 and does not output the internal image data 43.

  At this time, the second selection unit 44 follows the selection state of the second selection signal 21. For example, if the second selection signal 21 is a 4-bit signal, one of the selection states from the first selection state to the sixteenth selection state is determined.

  For example, when the second selection signal is 0000 (first state), the second selection unit 44 selects predetermined color data (for example, all white) from the internal image data 43 and sets it on the setting screen. Data 43A is generated and output.

  When the second selection signal is 0001 (second state), the second selection unit 44 selects predetermined color data (for example, all green), generates it as setting screen data 43A, and outputs it. .

  In this way, the second selection signal 21 is input to the switching unit 14, and the switching unit 14 selects predetermined color data from the internal image data 43 according to the selection state of the second selection signal 21. Thus, the setting screen data 43A is generated.

  That is, when the detection unit 13 detects that there is no external synchronization signal 19 and the first selection signal 20 is in the second state (for example, the low state), the switching unit 14 uses the internal image data 43 as the setting screen data. 43A and output setting screen data 43A.

  The above contents are summarized below. A switching unit 14 to which the internal image data 43 in the storage unit 7 is input, the first selection signal 20 is input, and the external image data 18 is input is provided.

  When the detection unit 13 detects that there is no external synchronization signal 19, the switching unit 14 determines whether the first selection signal 20 is in the internal state (for example, a high state or a low state). The image data 43 or the setting screen is output.

  When the detection unit 13 does not detect the external synchronization signal 19 and the first selection signal 20 is in the first state, the timing control unit 16 signals the internal synchronization signal 33, the clock signal 46, and the internal image data 43. To process.

  As a result, the timing control unit 16 outputs the gradation reference voltage 24, the timing signal 47 (strobe signal, start pulse, etc.), and image data 25 (for example, a logo display) to the signal driving unit 9.

  Further, the timing control unit 16 outputs a timing signal 48 (a clock pulse signal, a frame signal, etc.) to the scan driving unit 10.

  The liquid crystal panel 11 includes, for example, a plurality of signal electrodes formed on a lower glass substrate, a plurality of scanning electrodes, a TFT formed near the intersection thereof, and a pixel electrode ( (Both not shown).

  Further, the liquid crystal panel 11 includes a common electrode provided on the upper glass substrate, a color filter, a liquid crystal (both not shown) provided between the lower glass substrate and the upper glass substrate, and the like.

  The signal driver 9 outputs the gradation voltage 26 to each signal electrode provided on the liquid crystal panel 11 to drive the liquid crystal panel 11.

  The scanning drive unit 10 outputs a scanning voltage 49 to each scanning electrode provided on the liquid crystal panel 11 to drive the liquid crystal panel 11.

  Thus, in the above case, the liquid crystal panel 11 displays a logo or the like according to the internal image data 43.

  Next, when the detection unit 13 does not detect the external synchronization signal 19 and the first selection signal 20 is in the second state, the timing control unit 16 sets the internal synchronization signal 33, the clock signal 46, and the setting screen data. 43A is signal-processed.

  As a result, the timing control unit 16 outputs the gradation reference voltage 24, the timing signal 47, and the image data 25A (which conforms to the setting screen data, not shown) to the signal driving unit 9.

  The timing control unit 16 outputs a timing signal 48 to the scan driving unit 10.

  As a result, the liquid crystal panel 11 displays a setting screen (for example, the entire screen is green) according to the setting screen data 43A.

  Thereafter, when the detection unit 13 detects the external synchronization signal 19, the timing control unit 16 processes the external synchronization signal 19, the clock signal 46 </ b> A (not shown), and the external image data 18.

  As a result, the timing control unit 16 performs the gradation reference voltage 24, the timing signal 47A (not shown), and the image data 25B (following the external image data 18 but not shown) with respect to the signal driving unit 9. Is output.

  The timing control unit 16 outputs a timing signal 48 </ b> A (not shown) to the scan driving unit 10.

  As a result, the liquid crystal panel 11 performs display according to the external image data 18 sent from the in-vehicle navigation body, for example.

  Next, the image generation unit 12 will be described mainly according to FIG. The image generation unit 12 includes an internal synchronization signal generation unit 27, an interface circuit 39, and a color selection unit 40.

  The interface circuit 39 includes a counter 50, a controller 51, a selection unit 52, and a register 53. The counter 50 and the controller 51 are connected. The selection unit 52 is connected to the counter 50, the controller 51, and the register 53.

  The counter 50 outputs an address signal 42 to the storage unit 42. The storage unit 7 outputs 16-bit internal image data 43 to the selection unit 52.

  The color selector 40 includes a first selector 55a, a second selector 55b, a third selector 55c, a sixteenth selector 55p (a total of 16 selectors), and a selector 54. .

  As described above, the image generation unit 12 is provided between the storage unit 7 and the switching unit 14. The image generation unit 12 includes a color palette (that is, the first selection unit 55a to the sixteenth selection unit 55p).

  Next, the operation of the color selection unit 40 will be described. There are 16 color palettes (55a to 55p).

  Immediately after the power is turned on, the color information (R, G, B × 6 bits = 18 bits) is stored from the storage unit 7 for each color palette (55a to 55p).

  The interface circuit 39 reads the 16-bit internal image data 43 from the storage unit 7.

  Each piece of 16-bit data contains image data for 4 pixels (1 pixel is 4 bits). The selection unit 54 reads 16-bit data from the storage unit 7.

  The selection unit 54 selects 4-bit data from the 16-bit data. The 4-bit data indicates 16 ways. For example, if the data is 0000, the first selection unit 55a is indicated. If the data is 0001, the second selection unit 55b is indicated.

  If the selection unit 54 outputs 0000 data, the first selection unit 55a is selected. The first selection unit 55a outputs 18-bit image data, and data from the first pixel to the fourth pixel is output.

  Next, when the second 16-bit internal image data 43 is output from the storage unit 7, the same operation as the first operation described above is repeated. In this way, data from the fifth pixel to the eighth pixel is output. In this way, the second image data is written.

  Further, when the display (for example, 1/60 second) of the image data 25 of the first frame is finished on the liquid crystal panel 11, the color data (18 bits) of each color palette (55a to 55p) can be rewritten.

  If each color palette (55a to 55p) is used, the storage unit 7 may store data of 4 bits × pixel. Therefore, if the color palette is used, the memory capacity of the storage unit 7 can be reduced to about 4/18 = 22.2% when the color palette is not used.

It is a block diagram of the liquid crystal display device 1 which concerns on the Example of this invention. 2 is a block diagram of an integrated circuit 5 used in the liquid crystal display device 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 7 Memory | storage part 9 Signal drive part 10 Scan drive part 11 Liquid crystal panel 12 Image generation part 13 Detection part 14 Switching part 16 Timing control part 18 External image data 19 External synchronization signal 20 1st selection signal 21 2nd selection signal 43 Internal image data

Claims (5)

A detection unit that detects the presence or absence of an external synchronization signal, a storage unit, a switching unit to which internal image data in the storage unit is input, external image data is input, and a first selection signal is input; and a liquid crystal panel; A signal driving unit and a scanning driving unit that drive the liquid crystal panel, and a timing control unit that outputs at least each timing signal to each driving unit, and the detection unit detects the absence of the external synchronization signal. In this case, the switching unit outputs the internal image data or the setting screen data to the timing control unit according to a selection state of the first selection signal. 2. The liquid crystal display device according to claim 1, wherein when the first selection signal is selected to be in the first state, the switching unit outputs the internal image data for displaying a logo. 2. The liquid crystal display according to claim 1, wherein when the first selection signal is selected to be in the second state, the switching unit converts the internal image data into setting screen data and outputs the setting screen data. apparatus. The liquid crystal display device according to claim 1, wherein an image generation unit is provided between the storage unit and the switching unit, and the image generation unit includes a color palette. A second selection signal is input to the switching unit, and according to a selection state of the second selection signal, the switching unit selects the predetermined color data from the internal image data, whereby the setting screen is displayed. 4. The liquid crystal display device according to claim 3, wherein data is generated.

Images