JP4572156B2 - Liquid crystal display - Google Patents

Description

The present invention relates to a liquid crystal display device configured by combining a plurality of components, and more particularly, to a liquid crystal display device capable of checking whether or not a combination of components is correctly performed.

  As an example of assembling an electronic device, an assembly of a liquid crystal display device will be described as an example. In a liquid crystal display device, a liquid crystal panel and a drive circuit that drives the liquid crystal panel according to image data are basic components. The transmissive liquid crystal panel irradiates light from the back surface of the liquid crystal using a backlight. The backlight is driven by using an inverter board incorporating an inverter circuit.

  By the way, a liquid crystal panel and a backlight of a liquid crystal display device often adopt a multi-vendor system in which products of a plurality of companies are purchased because of supply quantity and price. It goes without saying that detailed specifications such as the oscillation frequency, lamp current, and open voltage applied to the backlight of the liquid crystal panel may differ depending on the product from which the product is purchased. On the other hand, even if the liquid crystal panel is different, the same inverter board is used as the basic circuit, and it is possible to cope with it by adjusting the circuit adjustment portion for changing the output characteristics of the circuit. Specifically, a circuit is assembled so that output characteristics such as an oscillation frequency, a lamp current, and an open circuit voltage can be changed in advance, and several constant adjustments may be made so as to correspond to the liquid crystal panel used in combination.

  Therefore, at the site of assembling the liquid crystal display device, for the backlights of various liquid crystal panels, exactly the same inverter board in appearance is simply used in combination with different adjustment contents of the adjustment circuit. . For this reason, when assembling a liquid crystal display device on the same line using liquid crystal panels and backlights of a plurality of companies, there is a possibility that an error occurs in that inverter boards having different adjustment contents are mistakenly incorporated. Moreover, even if such misuse is performed, there are many cases where the adjustment contents are slightly different, for example, the lamp current is slightly different. Therefore, as a liquid crystal display device, the display operation is often performed in a state close to normal, and further, the constant adjustment of the inverter board is not correct in the inspection at the time of manufacturing after performing fine adjustment related to display such as brightness manually or automatically. It becomes difficult to detect that

  Therefore, conventionally, proposals have been made to distinguish the same-shaped inverter boards having different adjustment contents in appearance. As one proposal, the position of the screw holes for attachment when the inverter board is attached to the substrate of the liquid crystal display device is changed according to the adjustment contents. Thereby, since an inverter board other than each corresponding to each of the backlights cannot be mounted on the substrate, a correct combination can always be ensured.

  However, in order to realize this proposal, it is necessary to make or change the mold of the board according to the screw hole of each inverter board. As a result, there is a problem that a considerable cost is required for individually preparing the molds of the corresponding substrates, which becomes an obstacle to adopting the multi-vendor system.

  FIG. 5 shows a main part of a liquid crystal display device using an inverter board according to another conventional proposal. The liquid crystal display device 100 includes an inverter board 101 and a scaler board 102. The inverter board 101 is supplied with power from a power supply unit (not shown) and controls lighting of a backlight (not shown). The inverter board 101 and the scaler board 102 are provided with connectors 111 and 112 for connecting them. Further, the inverter board 101 is provided with a control IC (Integrated Circuit) 113 that receives the power supply and controls the backlight.

  One end of the corresponding jumper wires 121 to 123 for the corresponding backlight type is connected to the connector 111 on the inverter board 101 side, and the other end is connected to one end of the jumper resistor land portion 131 to 133, respectively. ing. The other ends of the jumper resistor land portions 131 to 133 are connected in common and connected to the input terminal 114 for activation of the control IC 113.

  On the other hand, the scaler board 102 is a board in which a scaler IC (Integrated Circuit) 116 for resolution conversion is incorporated. One end of jumper wires 141 to 143 corresponding to the type of the corresponding backlight is also connected to the connector 112 of the scaler board 102, and the other end is connected to one end of the jumper resistor land portion 151 to 153. Yes. The other ends of the jumper resistor land portions 151 to 153 are connected in common and connected to an output terminal 117 for starting the scaler IC 116. Here, each of the jumper resistor land portions 131 to 133 and 151 to 153 is composed of a pair of lands, although not shown.

  In the proposed liquid crystal display device 100, first, a pair of lands constituting any one of the jumper resistor land portions 151 to 153 corresponding to the type of backlight (not shown) incorporated together with the scaler board 102. A resistor having a predetermined value is attached between them, or the pair of lands are short-circuited with a conductor such as solder, wire or metal piece. For example, if the type of the backlight is the first type, the pair of lands constituting the jumper resistor land 151 are short-circuited to change the resistance value from infinity to zero. In the case of the second type, only the pair of lands constituting the jumper resistor land portion 152 is short-circuited, and in the case of the third type, only between the pair of lands constituting the jumper resistor land portion 153. Will be short-circuited.

  On the other hand, the inverter board 101 has a predetermined interval between a pair of lands constituting the jumper resistor land 131 if the adjustment corresponding to the first type is similarly performed when the control IC 113 is adjusted. A resistance of a value is attached, or a short circuit between the pair of lands with a conductor such as solder. In the case of the second type, only a pair of lands constituting the jumper resistor land portion 132 is short-circuited, and in the case of the third type, only between a pair of lands constituting the jumper resistor land portion 133. Will be short-circuited.

  If such an adjustment is performed, the output terminal 117 for starting the scaler IC 116 is used for starting the control IC 113 via the connectors 111 and 112 only when the inverter board 101 is correctly attached to the liquid crystal display device 100. Connected to the input terminal 114. In other cases, both are insulated. Therefore, if the control IC 113 is set to output a backlight control signal only when the start-up ON signal is supplied from the scaler IC 116 to the start-up input terminal 114, the wrong inverter board 101 is liquid crystal. An abnormality can be easily detected when attached to the display device 100.

  However, the proposal shown in FIG. 5 requires jumper wires 121 to 123 and 141 to 143 and jumper resistance land portions 131 to 133 and 151 to 153 only for the type of backlight. Therefore, when the type of backlight increases, there is a problem that these parts and a space for arranging these parts are required.

  As mentioned above, although the problem about the part which comprises a liquid crystal display device was pointed out, when it is going to be surely integrated in the apparatus by the side of the main body side, the same problem exists.

  FIG. 6 shows a combination of an RF module and a telephone body in a mobile phone. A certain type of mobile phone 160 employs a configuration in which a radio telephone (RF) module 162 can be appropriately replaced with a common telephone body 161. Here, the RF module 162 is prepared for each wireless telephone communication system, and there are, for example, those for Japan and those for the United States as foreign countries. Further, since the RF module 162 is provided with a telephone number memory 163 that stores the telephone number of its own device, different telephone numbers can be used in the same telephone body 161. For example, the RF module 162 may be replaced when the telephone number is used separately for personal use and business use.

  In this cellular phone 160, the telephone number is written on the telephone body 161 and is not sold. Accordingly, the convenience is improved by replacing the RF module 162, but an error inadvertently attaching the wrong RF module 162 to the telephone body 161 occurs. Of these, it is assumed that there is a mistake that the RF module 162 having different telephone numbers having the same specifications is attached to the telephone body 161 and goes out. In this case, the outsider can make a call by combining the RF module 162 and the telephone body 161. However, since the telephone number is not the original number, the telephone to be received cannot be received. If you make a mistake with a foreign-specification RF module, you will not be able to communicate at all.

  Therefore, in the proposed mobile phone 160, the telephone main body 161 includes a main body control unit 165 that performs various controls in the main body. When the detection switch 166 detects this when the RF module 162 is attached, the RF module The telephone number is read from the telephone number memory 167 at the time of previous connection stored by reading from the telephone number memory 163 when the terminal 162 is connected. The comparison circuit 168 compares the previous telephone number with the telephone number read from the telephone number memory 163 in the RF module 162 attached this time. If the telephone body 161 and the RF module 162 were connected correctly last time, the two telephone numbers will not match if they are installed incorrectly.

When the wrong RF module 162 is attached in this way, the main body control unit 165 displays on the liquid crystal display unit 169 that the attachment is wrong. Thereby, the user can recognize the wrong attachment. A warning sound may be output from a speaker (not shown).
JP 2001-007918 (paragraph 0025, FIG. 2)

  In the proposal of Japanese Patent Laid-Open No. 2001-007918, it is assumed that there is a fact that parts are correctly attached once. However, when attaching a part in a predetermined apparatus for the first time on the assembly line, there is no history information on the correct attachment. For this reason, the proposal of this gazette cannot be adopted in such a case.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal that can confirm whether or not an appropriate one type of component is correctly selected from a relatively large number of components by using a small number of signal lines and without preparing a special device. It is to provide a display device .

In the present invention, (b) a power supply unit prepared to supply power to each part, and (b) a liquid crystal panel configured as a unit different from the power supply unit and displaying visual data and images, A liquid crystal panel unit in which a backlight for illuminating the liquid crystal panel is selected and arranged one by one from a plurality of types of predetermined products each having different characteristics;
(C) The above-described backlight in the liquid crystal panel unit is configured as a unit different from the power supply unit and the liquid crystal panel unit and receives power from the power supply unit via the first connector. An inverter circuit for driving the light source via the second connector, and constant adjusting means for adjusting output characteristics such as an oscillation frequency, a lamp current, and an open-circuit voltage output from the inverter circuit according to the type of the backlight. A panel identification circuit for outputting a panel identification signal corresponding to the control characteristic of the constant adjusting means via the third connector, and a parallel type identification signal composed of a plurality of bits corresponding to the output type of the inverter circuit. Is generated by a combination of logic outputs using pull-up resistors or pull-down resistors. A signal generating circuit receives the comparison result inputted through the third connector described above, the power supply unit described above operates the inverter circuit described above only when the comparison result of the above-mentioned type identification signal is set to match An inverter board unit including circuit operation control means for supplying the supplied power to the backlight through the second connector and lighting the backlight, and (d) the power unit and the liquid crystal panel unit. And a unit different from the inverter board unit, and is supplied with power from a panel identification number storage means storing a panel identification number corresponding to the type of the liquid crystal panel and the power supply unit via the fourth connector. And a panel identification signal from the panel identification circuit via the third connector. The presence / absence determination means for determining whether or not this matches the panel identification number, and the circuit operation control described above via the third connector for the comparison result determined by the match presence / absence determination means. The liquid crystal display device is provided with a scaler board unit including comparison means for sending to the means.

As described above, according to the present invention, since the identification information unique to each of the inverter board unit and the scaler board unit attached to the inverter board unit is determined to determine whether or not there is a match, for some reason. A malfunction can be detected even when the identification information on the inverter board unit side is out of order. In addition, when there is a mounting failure using the circuit operation control means, this result is output to the backlight side, so there is no need to provide a special output means, and the cost required for the inspection of the electronic equipment Cost reduction.

  Hereinafter, the present invention will be described in detail with reference to examples.

FIG. 1 shows an outline of the configuration of a liquid crystal display device as an electronic apparatus in an embodiment of the present invention. The liquid crystal display device 200 includes a power supply unit 201 that supplies power to each part of the device, a liquid crystal panel unit 202 that displays visual data and images, and an inverter board 204 that controls a backlight 203 of the liquid crystal panel unit 202, And a scaler board 206 that performs resolution conversion of the liquid crystal panel 205 in the liquid crystal panel unit 202. From the connector 207 of the power supply unit 201, the power supply voltage _{V CC} is supplied to the corresponding connectors 208 and 209 of the inverter board 204 and scaler board 206.

  In the liquid crystal panel unit 202 of this embodiment, a transmissive liquid crystal panel 205 is disposed on the front surface of the unit, and a backlight 203 is attached to the back of the transmissive liquid crystal panel 205. The liquid crystal panel 205 is controlled by a display circuit 211 in units of pixels.

  As described with reference to FIG. 5, the inverter board 204 is provided with a control IC 222 that controls output characteristics such as an oscillation frequency, a lamp current, and an open voltage of the backlight 203 by an output characteristic control signal 221. The connector 223 of the display control unit 204 transmits the output characteristic control signal 221 to the connector 224 of the liquid crystal panel unit 202.

The control IC 222 is provided with a constant adjustment unit 225 so that its output characteristics can be adjusted in advance according to the type of the backlight 203. Of course, the control IC 222 itself may be individually manufactured in accordance with each control characteristic. A power input terminal 226 of the control IC222, a voltage _{V CC} are supplied through the power line 227 from the power supply unit 201. The power supply line 227 is also connected to the input side of the panel identification circuit 228. The panel identification circuit 228 is for outputting a panel identification signal 229 corresponding to the control characteristics of the control IC 222, and a specific configuration will be described later. In this embodiment, the panel identification circuit 228 outputs a panel identification signal 229 from the first to third output lines 231 to 233. The respective end portions of the first to third output lines 231 to 233 are connected to a connector 230 disposed at the end portion of the inverter board 204.

  On the other hand, the scaler board 206 includes a scaler IC 241 similar to the scaler IC 116 shown in FIG. 5, a firmware ROM (Read Only Memory) 242 storing a panel identification number as a comparison destination of the panel identification signal 229, and the inverter board 204 side. The connector 243 connected to the connector 230 is provided. One end of each of the first to third input lines 251 to 253 corresponding to the first to third output lines 231 to 233 on the connector 230 side is connected to the connector 243. The other ends of the first to third input lines 251 to 253 are connected to panel identification number input terminals 254 to 256 of the scaler IC 241, respectively. The collation data 259 is input from the output terminal 258 of the firmware ROM 242 to the collation terminal 257 of the scaler IC 241. Further, one end of an image signal line 262 for outputting an image signal using a high-speed signal transmission technique is connected to an LVDS (Low Voltage Differential Signing) output terminal 261 of the scaler IC 241. The other end of the image signal line 262 is connected to the connector 263. The connector 263 is connected to the connector 264 of the liquid crystal panel unit 202 so that the image signal 265 is supplied to the display circuit 211. A dip switch may be connected instead of the firmware ROM 242.

  An ON signal line 266 and a dimming signal line 267 are also connected between the scaler IC 241 and the connector 243. The on signal line 266 is a line that transmits an on signal for starting the supply of power to the backlight 203, and is connected to an on signal line 268 that connects the connector 230 and the control IC 222. The dimming signal line 267 is a line for transmitting a dimming signal for adjusting the brightness of the backlight 203, and is connected to the dimming signal line 269 that connects the connector 230 and the control IC 222. .

FIG. 2 shows the configuration of the panel identification circuit of this embodiment. The panel identifying circuit 228, the first to third pull-up resistor 271 to 273 is arranged to which the voltage _{V CC} is applied to one end each through a power line 227. The other end of the first pull-up resistor 271 is connected to the first output line 231, and the other end of the second pull-up resistor 272 is connected to the second output line 232. The other end of the third pull-up resistor 273 is connected to the third output line 233. The first output line 231 is connected to a first land 281 of a substrate (not shown). The second output line 232 is connected to the second land 282 of the substrate. The third output line 233 is connected to the third land 283 of this substrate. The fourth to sixth lands 284 to 286 adjacent to the first to third lands 281 to 283 are grounded.

In the panel identification circuit 228 having such a configuration, if the first and fourth lands 281 and 284 are made conductive by a conductor such as solder, the output of the first output line 231 becomes a low level. High level in non-conducting state. Similarly, if the second and fifth lands 282 and 285 are made conductive by a conductor such as solder, the output of the second output line 232 becomes low level, while the non-conductive state becomes high level. Become. Further, if the third and sixth lands 283 and 286 are made conductive by a conductor such as solder, the output of the third output line 233 becomes low level, whereas it becomes high level in a non-conductive state. . Therefore, eight types of panel identification signals 229 can be created by combining the logic levels of the first to third output lines 231 to 233. Therefore, the panel identification signal 229 can be selected from this type in accordance with the control characteristics of the control IC 222 shown in FIG. Of course, when the number of types of control characteristics of the control IC 222 is larger than this, by increasing the number n of output lines from three in this example, in general, 2 ⁿ types of panel identification signals 229 can be set. Become.

  Further, when the scaler IC 241 side can discriminate three or more values according to the voltage level, it is between the first and fourth lands 281 and 284, between the second and fifth lands 282 and 285, or By connecting an appropriate resistor between the third and sixth lands 283 and 286, short-circuiting, or non-conducting, more panel identification signals 229 can be set using the same number of output lines. Become.

FIG. 3 shows a state of initial control of the scaler IC when power is supplied to the liquid crystal display device that has been assembled. This will be described with reference to FIGS. Scaler IC241 inputs receives a supply voltage _{V CC} from the power supply unit 201 via the connector 209, a panel identification signal 229 from the panel identifying circuit 228 (step S301). Then, the verification data 259 stored in advance in the firmware ROM 242 for the liquid crystal display device 200 is read (step S302), and it is determined whether or not they match (step S303).

  For example, it is assumed that the verification data 259 is composed of 3-bit data “011” representing the liquid crystal panel unit 202 of the manufacturer A. The panel identification circuit 228 of the inverter unit 204 conducts only between the first and fourth lands 281 and 284 with a conductor, and between the second and fifth lands 282 and 285 and between the third and sixth lands 283, In the case where the non-conducting state is established between 286, the panel identification signal 229 is similarly 3-bit data “011”. Thus, when both match (step S303: Y), the scaler IC 241 assumes that the inverter unit 204 corresponding to the liquid crystal panel unit 202 is attached to the liquid crystal display device 200 and the ON signal line 266 has a predetermined logic level. An ON signal is output (step S304). This ON signal is supplied to the control IC 222 through the ON signal line 268.

  On the other hand, when the inverter unit 204 that does not correspond to the liquid crystal panel unit 202 is connected, the panel identification circuit 228 shown in FIG. 2 is short-circuited between lands at different locations or connected with resistors of other resistance values. It will be. Therefore, in this case, the panel identification signal 229 and the verification data 259 do not match (step S303: N). In this case, the scaler IC 241 ends the processing without outputting the ON signal to the ON signal line 266.

FIG. 4 shows how the control IC in the inverter unit is processed. Control IC222 is waiting to ON signal from the ON signal line 268 in a state where the voltage _{V CC} is supplied through a power line 227 arrives (step S321). When an ON signal is sent in the process of step S304 in FIG. 3 (Y), power is supplied to the backlight 203 in accordance with the dimming signal sent from the dimming signal line 269 and the dimming control is performed thereafter. Is performed (step S322).

  Therefore, if the panel identification signal 229 and the verification data 259 are different in step S303 of FIG. For this reason, the liquid crystal panel 205 is not irradiated with transmitted light from the back surface, and the screen remains dark. As a result, when the assembly of the liquid crystal display device 200 is inspected, it is easily found that a problem has occurred. The term “failure” used herein refers to a case where wrong verification data 259 is written in the firmware ROM 242 of the scaler board 206 for some reason, or when another abnormal situation such as a failure in the power supply unit 201 occurs. This is because a similar result may be obtained.

  As described above, according to this embodiment, since the liquid crystal panel unit 202 originally provided in the liquid crystal display device 200 is used as an output destination for error display, the inverter unit 204 is incorrectly installed without preparing a special output device. There is an advantage that it is possible to warn the outside of such troubles. For this reason, not only the inspection is simplified, but also the cost for detecting an installation error of the inverter unit 204 can be minimized. In other words, the inverter unit 204 additionally requires several signal lines and some resistors or conductors for conduction, and the scaler board 206 only has a means for holding the verification data 259 such as the firmware ROM 242 or the DIP switch. It is.

  As described above, in the embodiment, the verification data 259 is created using several pull-up resistors, but may be created using pull-down resistors. Further, in the embodiment, the verification data 259 is created by setting various resistances between the lands of the board. However, the verification data may be directly stored in the control IC. In the embodiments, the case where the present invention is applied to a transmissive liquid crystal panel has been described. However, the present invention can be applied to a reflective type that irradiates a liquid crystal panel with a light source from the front. Of course, it is obvious that the present invention can be applied to display devices other than liquid crystal and electronic devices other than display devices. The output device is not limited to the display device as in the present embodiment, and various kinds of devices such as a speaker that outputs sound, a light emitting means that outputs light, a heating means that generates heat, a cooling means that performs cooling, and the like. Output means.

It is a block diagram showing the outline | summary of the structure of the liquid crystal display device as an electronic device in one Example of this invention. It is a circuit diagram of the panel identification circuit of a present Example. It is a flowchart showing the mode of the initial control of the scaler IC when the power is supplied to the liquid crystal display device. It is a flowchart showing the mode of processing of control IC in an inverter unit. It is a block diagram showing the principal part of the liquid crystal display device using the inverter board by the other proposal of the past. It is a principal part block diagram which showed the combination of RF module and telephone main body in a mobile telephone.

Explanation of symbols

200 Liquid Crystal Display Device 202 Liquid Crystal Panel Unit 203 Backlight 204 Inverter Board 205 Liquid Crystal Panel 206 Scaler Board 222 Control IC
228 Panel identification circuit 229 Panel identification signal 241 Scaler IC
242 Firmware ROM
271 First pull-up resistor 272 Second pull-up resistor 273 Third pull-up resistor 281-286 Land

Claims (2)

A power supply unit prepared to supply power to each part;
The power supply unit is configured as different units, 1 and the liquid crystal panel for displaying visual data and images, a plurality of types of predetermined product having respective different characteristics and a backlight for illuminating the liquid crystal panel LCD panel units selected and arranged one by one,
The power supply unit and the liquid crystal panel unit are configured as units different from each other, receive power from the power supply unit via the first connector, and use the light source as the backlight in the liquid crystal panel unit as a second light source. An inverter circuit driven via a connector, constant adjusting means for adjusting output characteristics such as oscillation frequency, lamp current, and open voltage output from the inverter circuit according to the type of the backlight, and control characteristics of the constant adjusting means A panel identification circuit that outputs a panel identification signal corresponding to the above through a third connector, and a parallel type identification signal consisting of a plurality of bits corresponding to the type of output of the inverter circuit using a pull-up resistor or a pull-down resistor A type identification signal generation circuit that generates a combination of the logic outputs, and the third Receiving the comparison result inputted through the Kuta, the power supplied from the power supply unit is operated the inverter circuit only when the comparison result of the type identification signal is set to match via the second connector An inverter board unit provided with circuit operation control means for supplying to the backlight and lighting it;
The power supply unit, the liquid crystal panel unit, and the inverter board unit are configured as units different from each other, panel identification number storage means storing a panel identification number corresponding to the type of the liquid crystal panel, and a fourth connector from the power supply unit. When the power supply is received, a panel identification signal is input from the panel identification circuit via the third connector, and it is determined whether or not it matches the panel identification number. A liquid crystal display device comprising: a scaler board unit including comparison means for sending the comparison result determined by the means to the circuit operation control means via the third connector.   2. The liquid crystal display device according to claim 1, wherein the panel identification number storage means is a firmware ROM (Read Only Memory).

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