JPH0534843A - Light source temperature controller of image reader - Google Patents

Abstract

PURPOSE:To speedily raise the temperature of a fluorescent lamp to constant temperature by driving the fluorescent lamp and a heat generation body when temperature detected by a detector is lower than a constant value. CONSTITUTION:A thermistor 8 detects the temperature of the fluorescent lamp 4 and when the detected temperature is lower than previously stored optimum temperature, the fluorescent lamp 4 is driven by a temperature control means(CPU). The fluorescent lamp 4 heats itself by lighting and when the detected temperature of the thermistor 8 exceeds the optimum temperature, the temperature control means holds the fluorescent lamp 4 OFF. After read operation is started, a heater 7 is driven by the temperature control means when the detected temperature of the thermistor 8 is lower than the optimum temperature. Consequently, the fluorescent lamp 4 is heated. When the detected temperature of the thermistor 8 reaches the optimum temperature, the temperature control means powers off the heater 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source temperature control device for an image reading device using a fluorescent lamp as a light source for illuminating an original.

[0002]

2. Description of the Related Art Since the amount of light emitted from a fluorescent lamp greatly changes depending on the temperature of the fluorescent lamp, it has a great influence on the accuracy of image reading. Therefore, for example, as described in Japanese Utility Model Laid-Open No. 2-119243, the temperature of the fluorescent lamp is detected, and when the detected temperature is below a certain value, the fluorescent lamp is heated by a heater.

[0003]

Conventionally, the temperature of the fluorescent lamp is raised only by the heater during warm-up, and the temperature of the fluorescent lamp is adjusted only by the heater even after the reading operation. Therefore, it takes a long time to raise the temperature of the fluorescent lamp to a certain value.

[0004]

According to a first aspect of the present invention, there is provided a transparent document table on which a document is placed, and a fluorescent lamp which is reciprocally held along the lower surface of the document table. An optical system element that receives the reflected light from the original, a detector that detects the temperature of the fluorescent lamp, a heating element that is close to the fluorescent lamp along the rear surface of the original opposite to the original table, When the temperature detected by the detector is below a certain value, the temperature control means drives the fluorescent lamp and the heating element.

According to a second aspect of the present invention, in the first aspect, a plurality of detectors for detecting the temperature of the fluorescent lamp are arranged along the longitudinal direction of the fluorescent lamp, and the temperature detected by any one of the detectors. Is a constant value or less, the temperature to drive the fluorescent lamp or the heating element and keep the fluorescent lamp or the heating element in a non-driving state when the detection temperature of all the detectors reaches a constant value Control means were provided.

According to a third aspect of the present invention, in the first aspect, the temperature control means for turning on the fluorescent lamp until the detector detects a constant temperature when the power is turned on, and the temperature detected by the detector after the reading operation is changed. Temperature control means for driving the heating element when the temperature is below a certain value is provided.

According to a fourth aspect of the present invention, in the first aspect, the temperature control means for driving the fluorescent lamp and the heating element until the detector detects a constant temperature when the power is turned on, and the detector after the reading operation is shifted. And a temperature control means for driving the heating element when the detected temperature is less than a certain value.

[0008]

According to the invention of claim 1, the temperature of the fluorescent lamp can be quickly raised to a constant temperature by the heat emitted from the fluorescent lamp itself and the heat given from the heating element, based on the temperature detected by the detector.

According to the second aspect of the present invention, even when the temperature of the fluorescent lamp is partially low, the fluorescent lamp can be turned on and heated based on the detection operation of the detector located closest to the fluorescent lamp. By heating all parts of the fluorescent lamp to a certain temperature or higher, it is possible to avoid a situation where the light quantity of the fluorescent lamp is insufficient.

According to the third aspect of the present invention, during warm-up, the temperature of the fluorescent lamp can be raised to a constant temperature due to the heat generated by the fluorescent lamp itself, and after the read operation, the temperature of the fluorescent lamp can be adjusted by the heater. Therefore, after shifting to the reading operation, the fluorescent lamp can be turned on only for the reading operation, and therefore, the life of the fluorescent lamp can be extended.

According to the invention of claim 4, the temperature of the fluorescent lamp can be raised to a constant temperature by the heat of the fluorescent lamp itself and the heat of the heater during warm-up, and therefore the warm-up time can be shortened. Since the temperature of the fluorescent lamp can be adjusted by the heater after the reading operation is changed, the fluorescent lamp can be turned on only for the reading operation after the reading operation is changed, thus extending the life of the fluorescent lamp. You can

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the inventions of claims 1 and 3 will be described with reference to FIGS. As shown in FIG.
A movable body 3 is provided reciprocally in the sub-scanning direction along the lower surface of a transparent document table 2 on which the document 1 is placed. In this movable body 3, a straight tube type fluorescent lamp 4 whose axis is arranged along the width direction (main scanning) of the original 1, a gradient index lens 5 and a CCD image sensor 6 which are optical systems, respectively. And are installed. Further, a heater 7 is arranged in proximity to the rear surface of the fluorescent lamp 4 opposite to the original table 2, and
As shown in FIG. 3, a thermistor 8 which is a detector for detecting the temperature of the fluorescent lamp 4 is arranged in proximity.

The temperature control operation for heating the fluorescent lamp 4 in such a configuration will be described with reference to the flow chart shown in FIG. First, turn on the main switch.
Here, the temperature of the fluorescent lamp 4 is detected by the thermistor 8, and when the detected temperature of the thermistor 8 is equal to or lower than the optimum temperature stored in advance, the fluorescent lamp 4 is driven by the temperature control means. The temperature control means is composed of a CPU (not shown) that operates based on program data. When the fluorescent lamp 4 is turned on, the fluorescent lamp 4 is heated by its own heat generation, and when the temperature detected by the thermistor 8 reaches or exceeds the optimum temperature, the fluorescent lamp 4
Is kept off by the temperature control means. This process is warm-up, and then it is kept in a standby state.

After the read operation, if the temperature detected by the thermistor 8 is below the optimum temperature, the heater 7 is driven by the temperature control means and the fluorescent lamp 4 is heated.
When the detected temperature of the thermistor 5 reaches or exceeds the optimum temperature, the temperature control means cuts off the energization of the heater 7. When reading, the original 1 is illuminated by the fluorescent lamp 4,
The image of the original 1 is formed on the CCD image sensor 6 through the gradient index lens 5.

As described above, by performing the reading operation in a state where the temperature of the fluorescent lamp 4 reaches the optimum temperature, it is possible to irradiate the document 1 with the reference amount of light and to faithfully read the image of the document 1. Further, based on the temperature detected by the thermistor 8, the fluorescent lamp 4 is turned on to generate heat from the fluorescent lamp 4 itself and the heater 7.
The temperature of the fluorescent lamp 4 can be quickly raised to a constant temperature by the heat given from the.

As described in claim 2, a plurality of thermistors 8 (detectors) for detecting the temperature of the fluorescent lamp 4 are arranged along the longitudinal direction of the fluorescent lamp 4, and all thermistors 8 are detected when the power is turned on. Fluorescent lamp 4 until the thermistor 8 detects a constant temperature
Alternatively, the heater 7 may be driven. Thereby, the temperature change of each part of the fluorescent lamp 4 is detected by the individual thermistor 8, and the fluorescent lamp 4 is heated based on the detection result, so that all parts of the fluorescent lamp 4 can be heated to a constant temperature. it can.

A plurality of fluorescent lamps 4 for illuminating the original 1
Each fluorescent lamp 4 is provided with a heater 7 and one or a plurality of thermistors 8, and the temperature is detected by the thermistor 8 for each fluorescent lamp 4. If the detected temperature is below the optimum temperature, the fluorescent lamp 4 May be turned on to raise the temperature of the fluorescent lamp 4 by its own heat, or the temperature of the fluorescent lamp 4 may be raised by the heater 7. Thereby, even if there are variations in the temperature of each fluorescent lamp 4 and each heater 7, it is possible to accurately set the temperature for each fluorescent lamp 4.

Next, one embodiment of the invention of claim 4 is shown in FIG.
It will be described based on. Since the structures shown in FIGS. 2 and 3 are also applied to this embodiment, only the heating operation of the fluorescent lamp 4 will be described with reference to the flowchart shown in FIG. First, turn on the main switch. Thermistor 8
If the detected temperature of is less than or equal to the optimum temperature stored in advance,
The fluorescent lamp 4 and the heater 7 are driven by the temperature control means. This temperature control means is also composed of a CPU (not shown) that operates based on the program data. The fluorescent lamp 4 is heated by its own heat generated by lighting and the heat of the heater 7. When the temperature detected by the thermistor 5 reaches or exceeds the optimum temperature, the fluorescent lamp 4 and the heater 7 are maintained in a non-driving state by the temperature control means. It This process is warm-up,
After that, it is maintained in a standby state.

After the read operation, if the temperature detected by the thermistor 8 is below the optimum temperature, the heater 7 is driven by the temperature control means, and the fluorescent lamp 4 is heated.
When the detected temperature of the thermistor 5 reaches or exceeds the optimum temperature, the temperature control means cuts off the energization of the heater 7. The reading operation is performed in this state.

As described above, at the time of warming up, the fluorescent lamp 4 itself can be heated to a constant temperature by the heat generated by the fluorescent lamp 4 itself and the heat of the heater 7, and therefore, the warm-up time can be shortened. Since the temperature of the fluorescent lamp 4 can be adjusted by the heater 7 after the reading operation is shifted, the fluorescent lamp 4 can be turned on only for the reading operation after the reading operation is shifted, and therefore, the life of the fluorescent lamp 4 is reduced. Can be extended.

[0021]

According to the first aspect of the present invention, a transparent manuscript table on which a manuscript is placed, a fluorescent lamp which is relatively reciprocally held along the lower surface of the manuscript table, and a manuscript from the manuscript are provided. An optical system element that receives reflected light, a detector that detects the temperature of the fluorescent lamp, a heating element that is close to the fluorescent lamp along the back surface of the fluorescent lamp opposite to the platen, and detection by the detector When the temperature is below a certain value, the fluorescent lamp and the heating element are constituted by the temperature control means for driving, so that the heat generated from the fluorescent lamp itself and the heat given from the heating element are based on the temperature detected by the detector. With this, there is an effect that the temperature of the fluorescent lamp can be quickly raised to a constant temperature.

According to a second aspect of the present invention, in the first aspect, a plurality of detectors for detecting the temperature of the fluorescent lamp are arranged along the longitudinal direction of the fluorescent lamp, and the temperature detected by any one of the detectors. Is a constant value or less, the temperature to drive the fluorescent lamp or the heating element and keep the fluorescent lamp or the heating element in a non-driving state when the detection temperature of all the detectors reaches a constant value Since the control means is provided, even when the temperature of the fluorescent lamp is partially low, the fluorescent lamp can be turned on and heated based on the detection operation of the detector located closest to the fluorescent lamp. By heating all the parts to a certain temperature or higher, it is possible to avoid the situation where the light quantity of the fluorescent lamp is insufficient.

According to a third aspect of the present invention, in the first aspect, the temperature control means for turning on the fluorescent lamp until the detector detects a constant temperature when the power is turned on, and the temperature detected by the detector after the reading operation is changed. Since the temperature control means that drives the heating element when the temperature is below a certain value is provided, the temperature of the fluorescent lamp can be raised to a certain temperature by the heat generation of the fluorescent lamp itself during warm-up, and after the reading operation transitions, the fluorescent lamp is heated by the heater. Since the temperature of the lamp can be adjusted, the fluorescent lamp can be turned on only for the reading operation after the reading operation is shifted, and therefore, the life of the fluorescent lamp can be extended.

According to a fourth aspect of the present invention, in the first aspect, the temperature control means for driving the fluorescent lamp and the heating element until the detector detects a constant temperature when the power is turned on, and the detector after the read operation shifts. Since the temperature control means for driving the heating element when the detected temperature of the fluorescent lamp is equal to or less than a certain value is provided, the fluorescent lamp can be heated to a certain temperature by the heat generated by the fluorescent lamp itself and the heat of the heater during warm-up. Therefore, the warm-up time can be shortened, and the temperature of the fluorescent lamp can be adjusted by the heater after the read operation has been shifted. Therefore, the fluorescent lamp is lit only for the read operation after the read operation has been shifted. Can therefore be
It has the effect of extending the life of the fluorescent lamp.

[Brief description of drawings]

FIG. 1 is a flow chart showing an operation of heating a fluorescent lamp according to an embodiment of the inventions of claims 1 and 3.

FIG. 2 is a front view thereof.

FIG. 3 is a rear view of the fluorescent lamp.

FIG. 4 is a flow chart showing an operation of heating a fluorescent lamp according to an embodiment of the invention of claim 4;

[Explanation of symbols]

1 manuscript 2 Platen 4 fluorescent lights 5,6 Optical system element 7 heating element 8 detectors

Claims (4)

[Claims] 1. A transparent document table on which a document is placed, a fluorescent lamp which is relatively reciprocally held along the lower surface of the document table, and an optical system which receives reflected light from the document. An element, a detector that detects the temperature of the fluorescent lamp, a heating element that is located close to the fluorescent lamp on the opposite side of the original plate from the original plate, and the temperature detected by the detector is below a certain value The light source temperature control device for an image reading device is characterized by comprising temperature control means for driving the fluorescent lamp and the heating element. 2. A plurality of detectors for detecting the temperature of the fluorescent lamp are arranged along the longitudinal direction of the fluorescent lamp, and when the detected temperature of any one of the detectors is below a certain value, the fluorescent light is emitted. A temperature control means is provided for driving the lamp or the heating element and maintaining the fluorescent lamp or the heating element in a non-driving state when the detected temperatures of all the detectors reach a constant value. The light source temperature control device of the image reading device according to claim 1. 3. A temperature control means for turning on the fluorescent lamp until the detector detects a constant temperature when the power is turned on, and a heating element is driven when the temperature detected by the detector is below a constant value after the reading operation. The light source temperature control device for an image reading apparatus according to claim 1, further comprising temperature control means. 4. A temperature control means for driving the fluorescent lamp and the heating element until the detector detects a constant temperature when the power is turned on, and the temperature detected by the detector is below a constant value after the reading operation. 2. A light source temperature control device for an image reading apparatus according to claim 1, further comprising temperature control means for driving a heating element.