JPH05216013A - Display driving device - Google Patents

Abstract

(57) [Summary] [Purpose] The appearance can be automatically optimized according to the temperature at the time of shooting. An electro-optical display unit 6, a temperature detection unit 21 for detecting a temperature around the electro-optical display unit and generating a temperature detection signal, and a bias value for generating a bias value for the electro-optical display unit. Generating means 23, changing means for changing the bias value, storage means 22 for storing a plurality of bias values changed by the changing means for each temperature detection signal,
Bias value control means 2 that performs a statistical process on a plurality of bias values stored in the storage means, controls the bias value generation means based on the processing result, and determines the bias value.
6, S42, S43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display driving device for driving a display device such as a liquid crystal panel (hereinafter abbreviated as LCD) for displaying an operating state of electronic equipment.

[0002]

2. Description of the Related Art In recent years, in electronic devices such as cameras and personal computers, the amount of information to be displayed tends to increase, so that the amount of information that can be displayed is increased without enlarging the outer shape of the electronic device itself. There is an urgent need.

In order to achieve this purpose, in the past, the driving of the LCD, which was the static type in the past, is almost replaced with the dynamic type. This dynamic method is a method of controlling lighting or extinguishing of a plurality of segments on the same line by using multiplexing of drive signals, that is, cyclical rise and fall of drive voltage values. According to this method, it is possible to increase the number of displayable segments without increasing the number of LCD electrodes. In this case, the duty ratio is called 1/4 or the like according to the number of segments that a single electrode is responsible for.

In an extreme application, a display system called a dot matrix, which is a further development of the dynamic system and in which the display form can be arbitrarily changed by the drive circuit without being influenced by the shape of the segment, is often used. ing. In this system, the LCD is composed of segments of square points which are regularly arranged on the entire surface of the panel, and the LCD is driven by electrodes which are vertically and horizontally arranged in a matrix. In this method, a high duty ratio of 1/64 or more is usually adopted.
This duty ratio tends to be set higher in the future in both the dynamic system and the dot matrix system.

On the other hand, the LCD has temperature dependence and viewing angle dependence. The principle of the LCD is controlled by the voltage value applied to turn it on and off, but its threshold level has the property of changing with temperature. Therefore, when the above-mentioned multiplexed drive voltage is always constant, the boundary between display and extinguishing changes depending on the change in the environmental temperature. Specifically, there occurs a phenomenon that a segment that should be turned off at a high temperature is turned on, or a segment that should be turned off at a low temperature is turned off. Also, LC
Since D uses the deflected light, the boundary between turning on and off of the segment changes depending on the viewing angle.

In order to solve such temperature dependency and viewing angle dependency, it is sufficient to change the driving voltage value, that is, the bias value. Therefore, the conventional display driving device is provided with a dial outside the device and The method of interlocking the rotation with the value of the semi-fixed resistance and leaving the adjustment to the user himself / herself has been adopted. In addition, as a display drive device that solves only the temperature dependence, there is a display drive device in which a thermistor or the like is provided in a part of the drive circuit to automatically perform a certain temperature correction.

[0007]

However, in the above-described conventional display driving device, each time the user changes the environmental temperature and the viewing angle, the dial is rotated to change the bias value, and the adjustment is performed so that the image looks optimal. I had to.

Also, in the latter display driving device for automatically correcting the temperature, the temperature range in which the operation is effective is narrow, and moreover, the fine adjustment has to be performed every time the viewing angle is changed.

Especially for a camera, unlike general office equipment, it is expected that the frequency of adjustment will be high because the temperature range used is very wide. However, there is a possibility that an important photo opportunity will be missed due to the adjustment work.

An object of the present invention is to solve the above-mentioned problems and to provide a display drive device capable of automatically optimizing the appearance of the display means according to the temperature at the time of photographing.

[0011]

In order to solve the above-mentioned problems, the display driving apparatus according to the present invention detects the temperature around the electro-optical display means (6) and the temperature around the electro-optical display means. Temperature detection means (21) for generating a detection signal,
Bias value generating means (23) for generating a bias value for the electro-optical display means, changing means for changing the bias value, and a plurality of bias values changed by the changing means for each of the temperature detection signals. Storage means for storing (2
2) and a bias value control means (26) for statistically processing a plurality of bias values stored in the storage means and controlling the bias value generation means based on the processing result to determine the bias value. , S42, S43).

In this case, the changing means is a manual adjusting means (7, 8) capable of adjusting the bias value to an arbitrary value, and the storing means includes a plurality of adjusting means adjusted by the manual adjusting means. A bias value is stored for each of the temperature detection signals, and the Baice value control means performs statistical processing on the bias value stored in the storage means to generate a bias value corresponding to the temperature detection signal. In addition, the bias value generating means may be controlled.

[0013]

According to the present invention, a plurality of bias values adjusted according to the temperature at the time of photographing by the temperature detecting means are stored in the storage means, and the stored plurality of bias values are statistically processed by the bias value control means. By processing, the display of the electro-optical display means is automatically optimized through the bias value generation means.

[0014]

EXAMPLES Examples will be described below with reference to the drawings.
This will be described in more detail. FIG. 1 is an external view showing an embodiment of a display driving device according to the present invention. The display driving device of this embodiment is applied to a single-lens reflex camera 1. A lens 2 is attached to the camera 1, the subject is confirmed by a finder 4, and then a shutter button 3 is pressed to perform exposure.

A back cover 5 is attached to the back surface of the camera 1, and an LCD 6 is provided on the back cover 5. The LCD 6 displays the proper exposure conditions for the subject calculated by the photometry of the camera 1, and is driven by the dot matrix method.

The back cover 5 is provided with density adjustment buttons 7 and 8 next to the LCD 6. The density adjustment buttons 7 and 8 are buttons for adjusting the display density of the LCD 6, and when the density adjustment button 7 increases the display density of the LCD 6, the density adjustment button 8 lowers the density. Used when. In this embodiment, finally, the density adjustment of the LCD 6 is automatically performed, but the density adjustment buttons 7 and 8 are used to input the conditions including the photographer's preference.

In the camera 1, a plurality of mercury switches 9 are arranged inside the finder 4 so as to have a predetermined angular relationship. Here, the mercury switch 9 refers to one that detects the posture of mercury enclosed in a glass tube by contacting the electrode inside. As shown in FIG. 1, by arranging a plurality of mercury switches 9 inside the camera 1 so as to have a predetermined angular relationship, the posture of the camera 1 to which the mercury switch 9 is attached can be detected. .. Examples of the detected posture include a normal position, a vertical position, and an inverted position.

The mercury switch 9 is incorporated in the determination processing of the multi-division photometry by detecting the attitude of the camera 1, and by determining the top and bottom of the camera 1, the accuracy of proper exposure is improved. It is a well-known one used for this purpose. In this embodiment, as will be described later, the attitude detecting means by the mercury switch 9 is used for correcting the viewing angle dependence of the LCD.

FIG. 2 is a block diagram showing an embodiment of the display driving device according to the present invention. In FIG. 2, the camera 1
The electric circuit inside the back cover 5 is shown, and the left side corresponds to the camera 1 and the right side corresponds to the back cover 5 from the two-dot chain line.

First, the structure of the camera 1 will be described. The CPU 14 has a brightness signal for the subject from the photometry circuit 11, a sensitivity signal of the film being used from the film sensitivity detection circuit 12, an operation signal of the shutter button 3 from the switch detection circuit 13 and an internal signal of the camera 1. Various switch signals etc. that express the sequence progress situation,
Each is connected.

The output from the CPU 14 is, via the drive circuit 15, the shutter 1 that exposes the film for a predetermined time.
6, a diaphragm 17 that controls the amount of light passing from the lens 2 to the film, and a winding motor 18 that winds the film by one frame after exposure. Also, CP
The U 14 transmits a display signal and the like to the CPU 26 in the back cover 5 via a plurality of contacts (not shown).

Next, the structure of the back cover 5 will be described. C
In the PU 26, the density adjustment signal of the LCD 6 from any of the density adjustment buttons 7 and 8, the attitude signal of the camera 1 from the plurality of mercury switches 9, the display signal from the CPU 14 described above, and the temperature detection circuit 21. , And the LCD density signal from the storage circuit 22 are connected. Here, the memory circuit 22 has a bidirectional signal transfer format, and has a C
In addition to outputting LCD density signal to PU26, CP
The LCD density signal from U26 may be input.

The output signal of the CPU 26 drives the LCD 6 via the drive circuit 25 and also the DA converter 24.
Control the output voltage of. Conventionally, the concentration is adjusted by a semi-fixed resistance that is manually changed or a thermistor whose resistance value changes with temperature, but in this embodiment, the DA converter 24 is used.

The DA converter 24 includes a plurality of resistors 2
It is composed of a ladder resistor 23 composed of 3a to 23n,
Since the upper end of the ladder resistor 23 is fixed by the power supply voltage (not shown) and the lower end is fixed by the output of the DA converter 24 as described above, the divided voltage value between the resistors 23a to 23n is the output of the DA converter 24. Will be controlled by. Further, the divided voltage output between the resistors 23a to 23n is input to the drive circuit 25 and incorporated in the drive waveform for the LCD 6.

Next, the operation of the display drive device of this embodiment will be described. FIG. 3 is a flowchart showing a processing routine of the CPU of the camera to which the display drive device according to the embodiment is applied. This processing routine is started when the CPU 14 is powered on. The CPU 14 inputs the subject brightness signal from the photometry circuit 11 (step 30), inputs the film sensitivity signal from the film sensitivity detection circuit 12 (step 31), and then performs proper exposure based on the subject brightness signal and the film sensitivity signal. Calculate the condition (Step 3)
2). Next, the CPU 14 transmits the display data corresponding to the proper exposure condition to the CPU 26 of the back cover 5 (step 33).

Here, the CPU 14 causes the shutter button 3
It is detected whether or not a release switch (not shown) is turned on by the operation (step 34). If the release switch is not turned on, the process returns to step 30 and the above routine is repeated. When the release switch is turned on, the mirror (not shown) is retracted from the optical path (step 3
5), set the diaphragm 17 to a predetermined value (step 36),
By opening the shutter 16 for a predetermined time (step 3
7), projecting the subject light on the film. After the exposure, the motor 18 is rotated to wind up the film by one frame and the mirror, the diaphragm 17 and the like are restored (step 38). After this, return to step 30,
The above routine is repeated.

FIG. 4 is a flow chart showing a processing routine by the CPU in the back cover of the camera to which the display driving device according to the embodiment is applied. When the CPU 26 is powered on, this process is started. The CPU 26 waits for the display data to be transmitted from the camera 1 (step 40), and stores the transmitted display data in the storage circuit 22 (step 41). The storage location is RAM inside the CPU 26.
(Not shown).

Next, the CPU 26 averages the concentration data D ** in the table stored for each posture and each temperature in the storage circuit 22 stored at the time of the previous operation, and averages the concentration data D *. 0 is calculated (step 42). The details will be described in Table 1 described later.

Further, the CPU 26 inputs the current temperature detected by the temperature detection circuit 21 (step 43).
Next, the posture of the camera 1 detected by the mercury switch 9 is input (step 44). This step 43, 44
The DA converter 24 is driven by the density data optimum for the temperature and the attitude input in step 2, that is, the average density data D * 0 calculated in step 42 (step 45).
Then, the display data once stored in step 41 is output to the drive circuit 25, and the segments in the LCD 6 are selectively turned on (step 46).

Next, the CPU 26 determines whether or not the density adjustment button 7 has been turned on and an operation for increasing the density has been performed (step 47). On the other hand, it is determined whether or not the density adjustment button 8 has been turned on and an operation for lowering the density has been performed (step 48).

Density adjustment button 7 or density adjustment button 8
If the operation of is performed, the adjusted density data is incorporated to change D * 0 (step 49). This means that the driving which was driven by the average density data D * 0 in step 45 is replaced with the manually adjusted driving data only for this occasion. And D
The A converter 24 is driven by the changed density data D * 0 (step 50).

The CPU 26 drives the drive circuit 25 based on the display data once stored in step 41 or step 56 described later (step 51). As a result, the density of the LCD 6 is adjusted.

Here, it is determined whether or not the operation of the density adjustment button 7 or the density adjustment button 8 has been interrupted (turned off) (step 52). If it remains on, step 49
By repeating the processing from 1 to 3, the density of the LCD 6 is continuously changed.

Density adjustment button 7 or density adjustment button 8
When is turned off, the stored density data is moved up by one column (step 53). First, D * 2
The concentration data D * 0 incorporated into * 1 and finally the final manually adjusted concentration data are incorporated into D * 5 (step 54). Here, the data in D * 0 is not erased, but is copied in D * 5. In steps 55 and 56, similarly to steps 40 and 41, data reception and data storage are performed.

[0035]

[Table 1]

Next, referring to Table 1, a more specific description will be given. Table 1 is a table showing a part of the density data map in the memory circuit 22. First, "normal position", "vertical position", "inverted position", and the like are prepared as major categories as posture types. In addition, each major category has a temperature range of "-20
℃ or less "," -20 ℃ to 0 ℃ "," 0 ℃ to +20 "
“° C” and “+ 20 ° C or higher” are prepared as small categories. Then, in each sub-class, data 1 to data 5 are stored as five raw data, and further, data 0 is stored as an average value data of five raw data or manually adjusted data.

As a typical example, Table 1 shows only the "normal position" map. The process of Table 1 will be described below in association with each step of FIG. Here, for ease of explanation, the posture is “normal photographing” and the temperature is “+ 20 ° C. or higher”.
And

First, in step 49, it means that the latest manually adjusted density data is incorporated in D40. D40 is adopted for display driving in the subsequent step 50. Further, in steps 53 to 54, the oldest data D41 is discarded,
Instead, D42 is installed, D42 is installed D43, D43 is installed D44, and D45 is installed D4.
Perform processing to incorporate 0. That is, each data is moved up to be updated as the latest data collection. At this time, the latest data D40 also exists as D41 as it is. The above processing is executed for the portion relating to the posture and temperature at that time when the density change buttons 7 and 8 are turned on. In step 42, the numerical values of data 1 to data 5 are averaged for each subclass to obtain the value of data 0. Since this is immediately after the start of operation, the LCD 6 must be displayed first, but the optimum density condition is set as the average value of the data 1 to data 5 accumulated in the past.

In the embodiment described above, the data amount is set to 5 for ease of explanation, but the processing may be performed with more data. Further, in order to obtain the optimum bias value, the average value may be an arithmetic mean or a square mean. If the root mean square is used, the user's preference will be more prominent. Further, the maximum value and the minimum value may be excluded to be obtained. In this way, data in extreme usage environments can be excluded. Furthermore, the optimum value may be obtained based on other statistical processing such as weighting. In this embodiment, the method of changing the output value of the DA converter and changing the bias value of the LCD has been described, but any method may be used as long as the bias value of the LCD can be optimized. ..

[0040]

As described in detail above, according to the present invention, based on a plurality of data matched to the temperature at the time of photographing,
Since the appearance of the electro-optical display means is automatically optimized, it is possible to eliminate the extra work of adjusting the appearance by changing the bias value by turning the adjustment dial each time it is used. Therefore, in the case of the camera, since it is possible to immediately check the photographing information together with the photographing preparation operation or the temperature change at the time of photographing, it is possible to avoid missing an important photo opportunity.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of a display driving device according to the present invention.

FIG. 2 is a block diagram showing an embodiment of a display driving device according to the present invention.

FIG. 3 is a flowchart showing a processing routine of a CPU of a camera to which the display driving device according to the embodiment is applied.

FIG. 4 is a flow chart showing a processing routine by a CPU in the back cover of the camera to which the display driving device according to the embodiment is applied.

[Explanation of symbols]

 1 camera 2 lens 3 shutter button 4 viewfinder 5 back cover 6 LCD 7,8 density adjustment button 9 mercury switch 11 photometric circuit 12 film sensitivity detection circuit 13 switch detection circuit 14 CPU 15 drive circuit 16 shutter 17 aperture 18 winding motor 21 temperature Detection circuit 22 Storage circuit 23 Resistance ladder 24 DA converter 25 Drive circuit 26 CPU

Claims (2)

[Claims] 1. An electro-optical display unit, a temperature detection unit for detecting a temperature around the electro-optical display unit to generate a temperature detection signal, and a bias value for the electro-optical display unit. Bias value generating means, changing means for changing the bias value, storage means for storing a plurality of bias values changed by the changing means for each of the temperature detection signals, and a plurality of biases stored in the storage means And a bias value control unit that determines the bias value by performing statistical processing on the value and controlling the bias value generation unit based on the processing result. 2. The change means is a manual adjustment means capable of adjusting the bias value to an arbitrary value, and the storage means uses a plurality of bias values adjusted by the manual adjustment means as the temperature detection signal. The bias value control means performs statistical processing on the bias value stored in the storage means to generate the bias value corresponding to the temperature detection signal. The display drive device according to claim 1, wherein the display drive device is controlled.