JP2001306053A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of deciding a correct OEM destination, even when an analog input voltage value becomes unstable at the establishing of an OEM destination, based on an analog input voltage value to a microcomputer. SOLUTION: In a display device which is made so as to establish an OEM' destination, based on an analog input voltage value to be inputted to a controller and to change over one part of a software processing according to the decided OEM destination, this device is provided with a means which decides an OEM destination based on an analog input voltage value, when the value is stable. Also it stores the OEM destination in a nonvolatile memory at the performing the establishing processing of the OEM destination and a means which decides an OEM destination based on OEM destination data stored in the nonvolatile memory, when the value is unstable at the time of performing the deciding processing of the OEM destination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a display device such as a liquid crystal projector.

[0002]

2. Description of the Related Art In recent years, OEM products have been increasingly used as a means for reducing product development costs. OEM
(Original Equipment Manufacturing) means that one company receives a request and manufactures a product of another company, which is also translated as "manufacturing of a partner brand product".

[0003] For example, if a manufacturer with a sales force performs new development in-house, it takes time and money, so it is often necessary to request a company that has already developed products to develop the products, buy them and sell them. , A typical OEM configuration.

In the case of OEM products, depending on the OEM, there are cases where only the appearance such as a logo mark is changed. In addition, the number of cases where the operation is differentiated by partially changing the software is increasing. At this time, the OEM product manufacturer may prepare different software for each OEM destination. However, software rationalization, that is, software that can be used by all OEM destinations, and software for each OEM destination are used. It is better to change the usage of
Software maintainability and quality can be improved. Therefore, it is necessary to recognize the OEM destination by some method. That is, it is necessary to obtain data for identifying the OEM destination.

One example of obtaining data for identifying an OEM destination is a method based on an analog input voltage value. This is a method in which an input analog voltage is converted into digital data using an A / D converter or the like built in a microcomputer, and an OEM destination is determined based on the digital data.

However, in this method, when the analog input voltage value is unstable, digital data cannot be determined.
As a result, the OEM destination may not be determined. In particular, in the case of a liquid crystal projector, the analog input voltage value tends to be unstable when a lamp for projecting a liquid crystal image on a screen is turned on. If the OEM destination cannot be determined, various problems occur.

For example, in a liquid crystal projector, a part of the screen display is different for each OEM destination, but if the OEM destination is determined by mistake, a screen for an OEM destination different from the original OEM destination is displayed. Inconvenience occurs. Therefore, it is necessary to safely and reliably determine the OEM destination.

[0008]

SUMMARY OF THE INVENTION According to the present invention, when an OEM destination is determined based on an analog input voltage value to a microcomputer, an accurate OEM destination is determined even when the analog input voltage value becomes unstable. It is an object of the present invention to provide a display device capable of performing the operation.

[0009]

A first display device according to the present invention determines an OEM destination based on an analog input voltage value input to a control device, and executes a software process in accordance with the determined OEM destination. When the analog input voltage value is stable during the OEM destination determination processing, the OEM destination is determined based on the analog input voltage value and the OEM destination data is stored in a non-volatile manner. Means for storing in memory, and OEM
If the analog input voltage value is unstable during the pre-determination process, the OEM stored in the nonvolatile memory
It is characterized by comprising means for determining an OEM destination based on previous data.

[0010] A second display device according to the present invention provides an OEM based on an analog input voltage value input to a control device.
In a display device in which the destination is determined and a part of the software processing is switched according to the determined OEM destination,
In the EM destination determination processing, the analog input voltage value is read a plurality of times, and first means for determining whether the OEM destination data corresponding to each read analog input voltage value matches, Corresponding OEM
Second means for repeating the processing by the first means each time it is determined that the preceding data does not match, and when the OEM destination data corresponding to each read analog input voltage value matches, the corresponding OEM input data corresponds to the analog input voltage value Even if the processing by the third means for storing the OEM destination data in the non-volatile memory and the processing by the first means are repeated a predetermined number of times while the OEM destination is determined based on the OEM destination data to be read, the read analog input voltage value is not changed. When the corresponding OEM destination data does not match, a fourth means for determining the OEM destination based on the OEM destination data stored in the nonvolatile memory is provided.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a liquid crystal projector.

This liquid crystal projector has a function of determining an OEM destination based on an analog input voltage value.
In FIG. 1, an input circuit for an analog input voltage value for determining an OEM destination is omitted. An analog input voltage value input circuit for determining the OEM destination will be described later (see FIG. 2).

The AC voltage input from the AC outlet 17 is converted by the active filter 11 into a DC voltage. The DC voltage obtained by the active filter 11 is sent to the main power supply circuit 12 and also to the lamp power supply circuit 15 via the lamp power switch 14.

The main power supply circuit 12 generates a power supply for a microcomputer (microcomputer) and a power supply for circuits other than the microcomputer. The microcomputer power generated by the main power supply circuit 12 is supplied to the microcomputer 10. The circuit power generated by the main power supply circuit 12 is supplied to the power terminals of each circuit via the circuit power switch 13.

The lamp power switch 14 and the circuit power switch 13 are on / off controlled by the microcomputer 10. When the lamp power switch 14 is turned on, a voltage is applied to the lamp 16 and the lamp 16 is turned on. When the circuit power switch 13 is turned on, power is supplied to each circuit. When the power is turned on by the operation unit 42,
Lamp power switch 14 and circuit power switch 1
3 is turned on.

The microcomputer 10 stores the program R
In addition to a storage device (not shown) such as an OM, a storage device (not shown) such as a RAM for storing necessary data, a nonvolatile memory 41 such as an EEPROM is provided. The microcomputer 10
Is input from the operation unit 42 such as a remote control transmitter and a keyboard.

The liquid crystal projector has an analog RBG for inputting an analog RBG signal from a computer.
An input terminal 18 and an AV input terminal 19 for inputting a composite video signal from a VCR, a DVD or the like are provided.

The analog RBG signal input to the analog RBG input terminal 18 is sent to a first input terminal of an input switch 22. The composite video signal input to the AV input terminal 19 is separated into a luminance signal and a chrominance signal by a Y / C separation circuit 20 and input to a video decoder 21.

The microcomputer 10 receives the presence / absence of a signal, a color system, and the like from the video decoder 21 and transmits control data corresponding to the signal to the video decoder 21. The video decoder 21 converts an input signal into an RBG signal and outputs it. The RBG signal from the video decoder 21 is sent to the second input terminal of the input switch 22. The input switch 22 is controlled by the microcomputer 10.

The signal selected by the input switch 22 is sent to an A / D converter 23. VCO
24 generates a sampling frequency according to an input signal based on control data from the microcomputer 10 and outputs the sampling frequency to the A / D converter 23. A / D converter 23
The input signal is sampled in synchronization with the sampling frequency input from the CO 24, and the obtained digital signal is output to the signal processing gate array 25.

The DRAM 33 has a display other than a video signal,
On-screen display data for performing so-called on-screen display is stored.

The signal processing gate array 25 switches between video data input from the A / D converter 23 and on-screen display data stored in the DRAM 33 and sends the data to the D / A converter 26.

The digital signal input to the D / A converter 26 is converted into an analog signal, and is input to the color signal driver 27. The color signal driver 27 performs color signal correction, such as brightness, based on the control data received from the microcomputer 10, and performs conversion of a DC curve according to the characteristics of the panel. The signal output from the color signal driver 27 is sent to the sample & hold circuit 28,
Sampling for output to 0 and 31 is performed.

Since collective writing is normally performed on the liquid crystal panels 29, 30, and 31 in units of six phases, that is, in units of six dots, the sample-and-hold circuit 28 captures and outputs data for six dots. From the sample & hold circuit 28, the liquid crystal panels 29, 30,
The corresponding data is sent to 31.

The timing controller 32 controls the timing of the sample and hold 28 and the liquid crystal panels 29, 30, 31 based on the control data received from the microcomputer 10.

FIG. 2 shows a voltage dividing circuit (input circuit for inputting an analog input voltage value for determining the OEM destination) 100, a microcomputer 10, and a nonvolatile memory 41 provided for determining the OEM destination.

The voltage dividing circuit 100 includes an optional resistor 101
And a pull-down resistor 102 in series. A connection point between the two resistors 101 and 102 is connected to a predetermined input terminal of the microcomputer. One end of the pull-down resistor 102 is grounded. One end of the option resistor 101 has a power supply of +5 which is a
V DC voltage is applied.

The resistance value Rx of the option resistor 101 is O
Determined according to the EM destination. The resistance value of the pull-down resistor 102 is 10 KΩ in this example. The microcomputer 10 has a built-in A / D converter (not shown) for converting an analog voltage value input via the voltage dividing circuit 100 into digital data. The resolution of the A / D converter is 8 bits in this example.

Table 1 shows the relationship between the analog input voltage value, the corresponding digital data, and the corresponding OEM destination.

[0031]

[Table 1]

In Table 1, when the optional resistor 101 does not exist (open), the input voltage becomes 0 V, the corresponding digital data becomes "0", and the corresponding OEM
The destination is “undefined OEM destination”. When the resistance value Rx of the optional resistor is, for example, 3.9Ω, the input voltage is 5 × 10 / (10 + 3.9) = 3.59 V, the corresponding digital data is “5”, and the corresponding OEM destination is “5. OEM destination 3 ". That is, the optional resistor 10
The OEM destination is determined by the presence / absence of 1 and the resistance value Rx of the optional resistor 101.

In the following description, the digital data shown in Table 1 is referred to as OEM destination data. Microcomputer 10
Stores the determined OEM destination data in the nonvolatile memory 41. This data is used when the analog voltage value is unstable.

FIG. 3 shows a part of the contents of the nonvolatile memory 41.

The nonvolatile memory 41 stores an area (address 0x00) for storing a keyword (0x55 in this example) indicating whether data is written in the nonvolatile memory 41, and stores OEM destination data. (Address 0x01) and the like.

FIG. 4 shows an OEM destination determination procedure executed by the microcomputer 10 when a power plug (not shown) of the liquid crystal projector is connected to the AC outlet 17.

When a power plug (not shown) of the liquid crystal projector is connected to the AC outlet 17, whether or not data has already been written to the nonvolatile memory 41, that is, whether or not the nonvolatile memory 41 is an unwritten product It is determined whether or not it is (step 1). Specifically, it is determined whether or not the keyword “0x55” is written at the address 0x00 in the nonvolatile memory 41.

If data has not been written to the nonvolatile memory 41, that is, if the keyword “0x55” has not been written to the address 0x00 in the nonvolatile memory 41, the address 0x
Write a keyword in 00 (step 2). The address “0x01” of the non-volatile memory 41 includes “Undefined OE”.
In the example, a natural number in the range of 0 to 3 is written (step 3).

In the above step 1, if data has already been written in the nonvolatile memory 41, that is, the keyword “0x00” is stored in the address 0x00 in the nonvolatile memory 41.
If "0x55" has been written, the process proceeds to step 4.

In step 4, 0 is set in the retry counter. This counter is used to count the number of times data is read from the A / D converter.

Thereafter, the OEM destination data corresponding to the input voltage input from the voltage dividing circuit 100 is read out using the A / D converter in the microcomputer 10 (step 5). A / D
Input voltage of converter and OEM output from A / D converter
The relationship with the preceding data (digital data) is as shown in Table 1. As can be seen from Table 1, digital values of 0 to 7 can be obtained as OEM destination data.

Next, after waiting for time (step 6), the A / D converter in the microcomputer 10 is used again to
OE corresponding to the input voltage input from voltage dividing circuit 100
The M destination data is read (step 7). The time waiting in step 6 is performed by the A / D converter for the OEM.
This is because, when the preceding data is read twice consecutively, it is vulnerable to short noise unless a certain interval is provided. Here, it is set to about 0.02 seconds as an example of waiting time.

Next, it is determined whether or not the first data read in step 6 matches the second OEM destination data read in step 7 (step 8). If they match, it is determined whether the OEM destination data read in step 6 or 7 is within an effective range in which the OEM destination can be determined (step 9). In the example of Table 1, the OEM
The valid range within which the destination can be determined is “4” to “7”.

If the OEM destination data read in step 6 or 7 is within the valid range in which the OEM destination can be determined, the OEM destination corresponding to the OEM destination data is determined as the OEM destination (step 10). And the confirmed OE
OEM destination data corresponding to the M destination and the non-volatile memory 41
It is determined whether the OEM destination data stored at the address “0x01” is the same (step 1).
1). If the two match, the current OEM destination determination processing ends. If they do not match, step 1
After writing the OEM destination data determined at 0 to the address “0x01” in the nonvolatile memory 41 (step 1)
2), the current OEM destination determination processing ends.

If it is determined in step 9 that the OEM destination data read in step 6 or 7 is not within the effective range in which the OEM destination can be determined, for example,
When the EM destination data is 0 to 3, "Undefined OEM"
Is determined as the OEM destination (step 17), and the current OEM destination determination processing ends.

If it is determined in step 8 that the first OEM destination data read in step 6 does not match the second OEM destination data read in step 7, the counter value of the retry counter is incremented by one. (Step 13). Then, it is determined whether or not the count value of the retry counter has become 10 or more (step 14).

If the count value of the retry counter is less than 10, the process returns to step 5 and the process of step 5 is executed again.

In step 14, if the count value of the retry counter becomes 10 or more, that is, even if the reading of one set of OEM destination data is repeated ten times twice, the reading is performed twice in each set. OE issued
If the M destination data does not match, the OEM destination data is read from the address 0x01 in the nonvolatile memory 41 (step 1).

OEM read from nonvolatile memory 41
It is determined whether or not the preceding data is within the valid range (step 16). If the OEM destination data read from the non-volatile memory 41 is within the valid range, the non-volatile memory 4
The OEM destination corresponding to the OEM destination data read from No. 1 is determined as the OEM destination (step 18).

OEM read from nonvolatile memory 41
If the destination data is not within the valid range, "Undefined OEM"
Is determined as the OEM destination (step 17), and the current OEM destination determination processing ends.

In step 17, "undefined OEM destination"
Is determined as the OEM destination, for example, the process returns to step 4 to perform the OEM destination determination processing again, disables the software, and executes the undefined OE.
It is conceivable to perform processing such as running software in a general-purpose usage method predetermined according to the M destination.

In the above-described embodiment, when the analog input voltage value is stable, the O / O is performed based on digital data (OEM destination data) corresponding to the analog input voltage value.
Determine the EM destination and store the relevant OE in the nonvolatile memory.
The M destination data is stored. On the other hand, if the analog input voltage value is unstable, the OEM
The OEM destination is determined by the destination data.

Therefore, even if the analog input voltage value is unstable at the time of the OEM destination determination processing, the OEM is kept in a state where the analog input voltage value is stable during the past OEM destination determination processing.
If the destination is determined, the correct OEM destination will be selected. For this reason, the stability of determining the OEM destination can be improved.

[0054]

According to the present invention, when the OEM destination is determined based on the analog input voltage value to the microcomputer, an accurate OE can be obtained even when the analog input voltage value becomes unstable.
M destination can be determined.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of a liquid crystal projector.

FIG. 2 is a diagram illustrating a voltage dividing circuit, a microcomputer, and a nonvolatile memory provided for determining an OEM destination;
FIG.

FIG. 3 is a schematic diagram showing a part of the contents of a nonvolatile memory 41;

FIG. 4 shows an OEM destination determination procedure executed by the microcomputer 10 when a power plug (not shown) of the liquid crystal projector is connected to the AC outlet 17;

[Description of Signs] 10 microcomputer 41 non-volatile memory 100 voltage divider 101 option resistor 102 pull-down resistor

Claims (2)

[Claims] 1. An OEM destination determining process, wherein an OEM destination is determined based on an analog input voltage value input to a control device, and a part of software processing is switched according to the determined OEM destination. At this time, if the analog input voltage value is stable, O
Means for determining the EM destination and storing the OEM destination data in the non-volatile memory, and when the analog input voltage value is unstable during the OEM destination determination processing,
Means for determining the OEM destination based on the OEM destination data stored in the non-volatile memory. 2. An OEM destination determining process, wherein an OEM destination is determined based on an analog input voltage value input to a control device, and a part of software processing is switched according to the determined OEM destination. First means for reading an analog input voltage value a plurality of times and determining whether or not OEM destination data corresponding to each read analog input voltage value matches; OEM destination corresponding to each read analog input voltage value; A second means for repeating the processing by the first means each time it is determined that the data does not match; when the read OEM destination data corresponding to each analog input voltage value matches, the data corresponds to the analog input voltage value; A third step of determining the OEM destination based on the OEM destination data and storing the OEM destination data in the nonvolatile memory.
Even if the processing by the means and the first means is repeated a predetermined number of times, if the OEM destination data corresponding to the read analog input voltage values does not match, the OEM destination data stored in the nonvolatile memory is added to the OEM destination data. OEM based
4. A display device, comprising: fourth means for determining a destination.