JPH1137837A - Light meter with display with internal illumination - Google Patents

Abstract

(57) [Problem] To provide illumination based on photometric data of an incident photometric unit without a photometric sensor that operates illumination of a display unit separately from a photometric unit of an exposure meter. An exposure meter that measures illuminance such as brightness on the surface or periphery of a subject when taking a picture and displays a measurement mode, individual measurement values, an aperture value or a shutter speed value of a camera on a display unit, When the photometric value of the light receiving portion of the light meter is equal to or less than a certain value, and the brightness of the display value of the display portion is insufficient and the display portion cannot be read (visually recognized), the display is performed based on the photometric value of the light receiving portion. In this configuration, the display unit is brightened by an illumination device so that the picture and numerical values of the display unit can be read even when the surroundings are dark.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light meter having a display unit with internal illumination, in which a display part of a light meter having a display unit is illuminated based on a measurement value of an incident light meter.

[0002]

2. Description of the Related Art In general, an exposure meter is used to measure the brightness of the surface of a subject or the interior of a room in order to take a picture with a proper exposure when taking a picture with a camera. 2. Description of the Related Art Information about shooting information such as an aperture value has been used. At this time, there is no problem if the numerical value or the like displayed on the display unit of the light meter can be read. However, there are cases where the room is dark or the measurement place is dark and cannot be read. In particular, recently, various devices using a liquid crystal display as these display means have been proposed. Regarding an external display, a light is emitted as a backlight on the back of the liquid crystal display so that the display can be visually recognized (measurement value can be read) even in the dark. A device provided with a diode or the like is known.

[0003] For this reason, misinterpretation often occurs, and photographing with improper exposure is often performed. In particular, the scale of the light meter cannot be read, so that it is necessary to rely on the intuition of an experienced measurer.

[0004]

However, with such intuition, an appropriate photograph could not be obtained, or a photograph having an inappropriate color tone could be obtained especially in the case of a color photograph. For this reason, a backlight method or the like for illuminating the display unit is employed. For example, it is known to manage the drive voltage of the liquid crystal display unit. But,
If the backlight lighting time is long, the battery is consumed greatly, and the battery needs to be replaced in a short time. Also, a detector for backlight illumination, for example, a CD, separately from the measuring unit of the exposure meter
In some cases, S is used and illumination is performed by changing the electrical resistance of the circuit at this time. That is, a sensor for detecting whether the brightness of the display unit is difficult to read is provided,
In some cases, the display unit is illuminated by the function of the detection sensor. However, in this case, the complexity of the electric circuit and the number of parts are large and the cost is high.

An object of the present invention is to provide an exposure meter whose display unit can be visually recognized even in darkness. It is another object of the present invention to provide a light meter that does not include a photometric sensor that operates the illumination of the display unit separately from the photometric unit of the light meter, but includes a display unit with internal illumination.

[0006]

Means for Solving the Problems The object of the present invention is to provide:
When taking a photograph, the illuminance such as the brightness of the surface or the periphery of a subject is measured, and the display unit displays a measurement mode, individual measurement values, an aperture value or a shutter speed value of a camera, and the like. When the photometric value of the light receiving unit is equal to or less than a certain value, and the brightness of the display value or the like of the display unit is insufficient and the display unit cannot be read (visually recognized), the display unit is illuminated based on the photometric value of the light receiving unit. This can be achieved by a configuration in which the brightness of the image is increased and the numerical value of the picture on the display unit is readable.

The display section is an EL luminous body, and the external brightness measured by a light receiving section (light bulb) through an incident light measuring section is less than a predetermined value. The above object can be achieved by performing illumination for a certain period of time. Further, the display of the measured value on the display unit is controlled according to the use mode of the light meter, and the above-described problem can be achieved by enabling the display unit to be illuminated for a short time when each mode is changed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a light meter having a display unit with internal illumination according to the present invention, the photometric value of the light receiving unit of the light meter is not more than a certain value, and the brightness of the display value or the like of the display unit is insufficient. And when the display unit cannot be read (visually recognized), the display unit is brightened by a lighting device based on the photometric value of the light receiving unit,
The internal illumination of the display unit is turned on using the measurement data at the time of measurement by the incident photometry unit. Therefore, at the time of reflection photometry, the ambient brightness is measured instantaneously by the incident photometry unit. This makes the display part brighter for several seconds, and the measured value of the reflection photometry can be read.

Further, in the light meter of the present invention, since various patterns and data are displayed on the display unit, it is necessary to illuminate the display unit brightly in order to confirm these display contents. The photometric value of the light receiving section of the incident photometric section is instantaneously measured, and it is determined whether the value is equal to or less than a predetermined value, and the internal illumination is turned on at the time of various measurements. It has never existed before. The data can be visually recognized at any measurement.

Further, the light meter having the display unit with the internal illumination according to the present invention needs to illuminate the display unit even when the mode is switched. Therefore, after performing the mode switching, perform simple photometry of the light received by the incident photometry unit, and instantaneously determine whether or not this measurement value has reached a constant value. The display unit can be visually recognized. According to the present invention, since the internal illumination is operated based on the photometry data of the incident photometry unit, an exposure meter having an internal illumination that does not require a sensor for detecting darkness can be manufactured at low cost. In addition, since the photometric data of the incident photometric unit is used when the mode is switched or the display unit is confirmed by software, the overall control is simplified.

The internal illuminating device of the light meter of the present invention is any one of an incandescent lamp, a light emitting diode and an EL illuminator, and emits light instantaneously based on photometric data of a light receiving portion of an incident photometric portion to visually recognize a display portion. Can be.

FIG. 1 is a schematic circuit diagram of a light meter having a display unit with internal illumination according to the present invention, and FIG. 2 is a plan view of an embodiment of the light meter according to the present invention. FIG. 3 is a flowchart of the photometric operation of the light meter of the present invention.

Reference numeral 1 denotes an exposure meter, on the surface of which is provided a liquid crystal display section 2 which is an EL luminous body. It is a place to display measured values when various modes and external brightness are measured. Reference numeral 3 denotes an incident light meter, in which a light sphere 3a as a light receiving unit is disposed. Reference numeral 4 denotes a reflected light meter. Reference numeral 5 denotes an on / reflection switch for switching the photometry mode between incident photometry and reflection photometry. Reference numeral 6 denotes a measurement switch, which is depressed when performing photometry, and causes the liquid crystal display unit 2 to display a measured value. Reference numeral 7 denotes a power switch of the light meter. 8 is a mode switch. 9 is a memory switch. 10 is a memory erase switch. Reference numeral 11 denotes a dial switch for switching between IS0 data, mode data, and each measurement range depending on a click position. Reference numeral 12 denotes IS0 for switching the IS0 display of the liquid crystal display unit 2.
This is a changeover switch.

FIG. 1 shows a circuit configuration of an exposure meter having a display unit with internal illumination according to the present invention. The term "external light receiving input" is the same as that of the light receiving unit of the incident light measuring unit. The photometric data of the incident light receiving unit and the reflected light receiving unit are amplified by a light receiving amplifier, and are amplified via an incident / reflection input switch.
/ D converted and input to the central control processing unit (CPU). Here, the measurement data of the incident photometry unit is compared with a predetermined value, for example, EV3. As a result, if the measured data is less than EV3, the "EL lighting booster circuit"
Is operated to turn on the EL of the liquid crystal display unit 2.

In the light meter of the present invention, when the photometry or another measurement mode switch is turned on, the photometry process is performed through the light receiving portion (light bulb) of the incident photometry portion, and this photometry value is converted into A / A.
When the D-converted data is equal to or less than the preset data, the backlight of the liquid crystal display unit 2 is turned on and illuminated for a fixed time (about 10 seconds), so that the measured value can be visually recognized. As a result, when the liquid crystal display unit 2 cannot be visually recognized at a brightness equal to or less than a certain fixed value, the liquid crystal display unit 2 automatically illuminates for a certain period of time. Therefore, the operator can easily read the measurement data. In addition, when the reflection photometry is being performed, a simple photometry is performed by instantaneously switching to the light receiving section 3a of the incident photometry section 3 in order to measure the ambient brightness. When the value is equal to or less than a predetermined value, the liquid crystal is determined in the same manner as described above. The display unit 2 is illuminated for a certain time. At the time of illumination photometry, the photometry time can be reduced as much as possible.

A flowchart for photometry of the light meter of the present invention shown in FIG. 3 will be described. First, after the power switch 7 is input, the input / reflection switch 5 for switching between incident and reflection photometry is switched to select the photometry mode between incident photometry and reflection photometry, and then the measurement switch 6 is pressed to perform photometry. . When performing the incident photometry, when the measured value exceeds a predetermined value, which is a preset reference level, for example, compared with EV3, no internal illumination is required.
When it is equal to or less than V3, EL (liquid crystal) is automatically turned on, and the light is turned on for a preset timer (10 seconds).

When performing photometry in the reflection mode, the mode is changed to the temporary incidence mode, and simple photometry is performed by the light receiving unit (light bulb).
The photometric data is compared, and if EV3 or less, the internal illumination is automatically performed, the EL is turned on for 10 seconds, and the measured value of the reflection photometric unit is displayed.

As described above, in the case of reflection photometry and other displays, photometry is performed by the light receiving unit of the incident photometry unit, and the photometric data values are compared. For 10 seconds, the photometry by the incident photometry unit is not performed, and another 10
It will light up for seconds.

[0019]

According to the present invention, the light meter provided with the display unit with the internal illumination is turned on by comparing the measured value of the light reception (photosphere) of the incident light measuring unit with the internal setting value. An exposure meter having a display unit with an internal illumination lamp can be provided at low cost without requiring a control circuit. In addition, useless illumination is not required for continuous photometry, so that battery consumption can be prevented and the device can be used for a long time.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of a light meter including a display unit with internal illumination according to the present invention.

FIG. 2 is a plan view of an embodiment of a light meter according to the present invention.

FIG. 3 is a flowchart of a photometric operation of the light meter of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Exposure meter 2 ... Liquid crystal display part 3 ... Incident light measuring part 3a ... Light bulb 4 ... Reflection light measuring part 5 ... Input / reflection changeover switch 6 ... Measurement switch 7 ... Power switch 8 ... Mode changeover switch 9 ... Memory switch 10 ... Memory Erase switch 11 ... Dial switch 12 ... IS0 selector switch

Claims (5)

[Claims] 1. An exposure meter that measures illuminance such as brightness on the surface or the periphery of a subject at the time of photographing and displays a measurement mode, individual measurement values, an aperture value or a shutter speed value of a camera on a display unit, and the like. When the photometric value of the light receiving unit of the exposure meter is equal to or less than a certain value, and the brightness of the display value or the like of the display unit is insufficient and the display unit cannot be read (visually recognized), the light measurement value of the light receiving unit is used. A light meter having a display unit with internal illumination, wherein the display unit is illuminated by an illumination device so that pictures and numerical values of the display unit can be read even when the surroundings are dark. 2. The display device according to claim 1, wherein when the external brightness measured through the incident photometric unit is equal to or less than a predetermined value, the display unit is illuminated for a predetermined period of time by using the measured data. Exposure meter provided with the display unit with internal illumination described in the above. 3. The light meter according to claim 1, wherein the display unit is an EL luminous body. 4. The display of a measured value on the display unit is controlled in accordance with a use mode of the light meter, and the display unit can be illuminated for a short time when each mode is changed. An exposure meter including the display unit with internal illumination described in 1, 2, or 3. 5. The display unit with internal illumination according to claim 1, wherein the internal illumination is any one of an incandescent light bulb, a light emitting diode, and an EL luminous body. Light meter.